diff --git a/core/api/test-current.txt b/core/api/test-current.txt
index d817c41d2b27..b8f2c5a85307 100644
--- a/core/api/test-current.txt
+++ b/core/api/test-current.txt
@@ -1361,6 +1361,7 @@ package android.location {
 package android.media {
 
   public final class AudioAttributes implements android.os.Parcelable {
+    method public static int[] getSdkUsages();
     method @NonNull public static String usageToXsdString(int);
     method public static int xsdStringToUsage(@NonNull String);
   }
@@ -1380,6 +1381,8 @@ package android.media {
     method @RequiresPermission("android.permission.QUERY_AUDIO_STATE") public int abandonAudioFocusForTest(@NonNull android.media.AudioFocusRequest, @NonNull String);
     method @Nullable public static android.media.AudioDeviceInfo getDeviceInfoFromType(int);
     method @IntRange(from=0) @RequiresPermission("android.permission.QUERY_AUDIO_STATE") public long getFadeOutDurationOnFocusLossMillis(@NonNull android.media.AudioAttributes);
+    method public static final int[] getPublicStreamTypes();
+    method public int getStreamMinVolumeInt(int);
     method public boolean hasRegisteredDynamicPolicy();
     method @RequiresPermission(anyOf={android.Manifest.permission.MODIFY_AUDIO_ROUTING, android.Manifest.permission.QUERY_AUDIO_STATE}) public boolean isFullVolumeDevice();
     method @RequiresPermission("android.permission.QUERY_AUDIO_STATE") public int requestAudioFocusForTest(@NonNull android.media.AudioFocusRequest, @NonNull String, int, int);
@@ -1403,6 +1406,7 @@ package android.media {
     method @RequiresPermission(android.Manifest.permission.MODIFY_AUDIO_SETTINGS) public static float getMasterBalance();
     method public static final int getNumStreamTypes();
     method @RequiresPermission(android.Manifest.permission.MODIFY_AUDIO_SETTINGS) public static int setMasterBalance(float);
+    method @NonNull public static String streamToString(int);
     field public static final int DEVICE_ROLE_DISABLED = 2; // 0x2
     field public static final int DEVICE_ROLE_NONE = 0; // 0x0
     field public static final int DEVICE_ROLE_PREFERRED = 1; // 0x1
@@ -1501,8 +1505,10 @@ package android.media.audiopolicy {
   }
 
   public final class AudioProductStrategy implements android.os.Parcelable {
+    method @NonNull public static android.media.AudioAttributes getDefaultAttributes();
     method public int getLegacyStreamTypeForAudioAttributes(@NonNull android.media.AudioAttributes);
     method public int getVolumeGroupIdForAudioAttributes(@NonNull android.media.AudioAttributes);
+    method public int getVolumeGroupIdForLegacyStreamType(int);
   }
 
 }
diff --git a/core/api/test-lint-baseline.txt b/core/api/test-lint-baseline.txt
index 1833ed50ce4f..1d0325866c21 100644
--- a/core/api/test-lint-baseline.txt
+++ b/core/api/test-lint-baseline.txt
@@ -71,6 +71,10 @@ ActionValue: android.telephony.mbms.vendor.VendorUtils#EXTRA_TEMP_LIST:
     
 
 
+AllUpper: android.media.audiopolicy.AudioProductStrategy#sDefaultAttributes:
+    Constant field names must be named with only upper case characters: `android.media.audiopolicy.AudioProductStrategy#sDefaultAttributes`, should be `S_DEFAULT_ATTRIBUTES`?
+
+
 ArrayReturn: android.app.UiAutomation#executeShellCommandRw(String):
     
 ArrayReturn: android.hardware.soundtrigger.SoundTrigger.KeyphraseSoundModel#KeyphraseSoundModel(java.util.UUID, java.util.UUID, byte[], android.hardware.soundtrigger.SoundTrigger.Keyphrase[]) parameter #3:
@@ -539,6 +543,8 @@ InterfaceConstant: android.telecom.PhoneAccountSuggestionService#SERVICE_INTERFA
     
 
 
+InternalField: android.media.audiopolicy.AudioProductStrategy#sDefaultAttributes:
+    Internal field sDefaultAttributes must not be exposed
 InternalField: android.telephony.ims.ImsConferenceState#mParticipants:
     
 
@@ -1091,8 +1097,14 @@ MissingNullability: android.location.LocationManager#getTestProviderCurrentReque
     
 MissingNullability: android.location.LocationRequest#writeToParcel(android.os.Parcel, int) parameter #0:
     
+MissingNullability: android.media.AudioAttributes#SDK_USAGES:
+    Missing nullability on field `SDK_USAGES` in class `class android.media.AudioAttributes`
+MissingNullability: android.media.AudioAttributes#getSdkUsages():
+    Missing nullability on method `getSdkUsages` return
 MissingNullability: android.media.AudioFocusInfo#writeToParcel(android.os.Parcel, int) parameter #0:
     
+MissingNullability: android.media.AudioManager#getPublicStreamTypes():
+    Missing nullability on method `getPublicStreamTypes` return
 MissingNullability: android.media.AudioRecordingConfiguration#AudioRecordingConfiguration(int, int, int, android.media.AudioFormat, android.media.AudioFormat, int, String) parameter #3:
     
 MissingNullability: android.media.AudioRecordingConfiguration#AudioRecordingConfiguration(int, int, int, android.media.AudioFormat, android.media.AudioFormat, int, String) parameter #4:
@@ -1109,6 +1121,8 @@ MissingNullability: android.media.AudioRecordingConfiguration#AudioRecordingConf
     
 MissingNullability: android.media.AudioRecordingConfiguration#AudioRecordingConfiguration(int, int, int, android.media.AudioFormat, android.media.AudioFormat, int, String, int, boolean, int, android.media.audiofx.AudioEffect.Descriptor[], android.media.audiofx.AudioEffect.Descriptor[]) parameter #6:
     
+MissingNullability: android.media.AudioSystem#streamToString(int):
+    Missing nullability on method `streamToString` return
 MissingNullability: android.media.PlaybackParams#setAudioStretchMode(int):
     
 MissingNullability: android.media.audiofx.AudioEffect#EFFECT_TYPE_NULL:
diff --git a/core/java/android/preference/SeekBarVolumizer.java b/core/java/android/preference/SeekBarVolumizer.java
index 400b312bb913..69a09fb9b7f1 100644
--- a/core/java/android/preference/SeekBarVolumizer.java
+++ b/core/java/android/preference/SeekBarVolumizer.java
@@ -214,7 +214,7 @@ public class SeekBarVolumizer implements OnSeekBarChangeListener, Handler.Callba
 
         return AudioManager.getAudioProductStrategies().stream()
                 .map(strategy -> strategy.getVolumeGroupIdForAudioAttributes(
-                        AudioProductStrategy.sDefaultAttributes))
+                        AudioProductStrategy.getDefaultAttributes()))
                 .filter(volumeGroupId -> volumeGroupId != AudioVolumeGroup.DEFAULT_VOLUME_GROUP)
                 .findFirst()
                 .orElse(AudioVolumeGroup.DEFAULT_VOLUME_GROUP);
diff --git a/media/java/android/media/AudioAttributes.java b/media/java/android/media/AudioAttributes.java
index 7e729d8c371f..ce5fa05caae7 100644
--- a/media/java/android/media/AudioAttributes.java
+++ b/media/java/android/media/AudioAttributes.java
@@ -333,6 +333,14 @@ public final class AudioAttributes implements Parcelable {
             USAGE_ASSISTANT,
     };
 
+    /**
+     * @hide
+     */
+    @TestApi
+    public static int[] getSdkUsages() {
+        return SDK_USAGES;
+    }
+
     /**
      * Flag defining a behavior where the audibility of the sound will be ensured by the system.
      */
diff --git a/media/java/android/media/AudioManager.java b/media/java/android/media/AudioManager.java
index a717a90c1c37..56a8b1673fac 100644
--- a/media/java/android/media/AudioManager.java
+++ b/media/java/android/media/AudioManager.java
@@ -387,6 +387,18 @@ public class AudioManager {
      */
     @Deprecated public static final int NUM_STREAMS = AudioSystem.NUM_STREAMS;
 
+    /** @hide */
+    private static final int[] PUBLIC_STREAM_TYPES = { AudioManager.STREAM_VOICE_CALL,
+            AudioManager.STREAM_SYSTEM, AudioManager.STREAM_RING, AudioManager.STREAM_MUSIC,
+            AudioManager.STREAM_ALARM, AudioManager.STREAM_NOTIFICATION,
+            AudioManager.STREAM_DTMF,  AudioManager.STREAM_ACCESSIBILITY };
+
+    /** @hide */
+    @TestApi
+    public static final int[] getPublicStreamTypes() {
+        return PUBLIC_STREAM_TYPES;
+    }
+
     /**
      * Increase the ringer volume.
      *
@@ -1065,6 +1077,7 @@ public class AudioManager {
      * @return The minimum valid volume index for the stream.
      * @see #getStreamVolume(int)
      */
+    @TestApi
     public int getStreamMinVolumeInt(int streamType) {
         final IAudioService service = getService();
         try {
diff --git a/media/java/android/media/AudioSystem.java b/media/java/android/media/AudioSystem.java
index 8134d6f8352d..ebb2e8729bb1 100644
--- a/media/java/android/media/AudioSystem.java
+++ b/media/java/android/media/AudioSystem.java
@@ -1995,7 +1995,8 @@ public class AudioSystem
     };
 
     /** @hide */
-    public static String streamToString(int stream) {
+    @TestApi
+    public static @NonNull String streamToString(int stream) {
         if (stream >= 0 && stream < STREAM_NAMES.length) return STREAM_NAMES[stream];
         if (stream == AudioManager.USE_DEFAULT_STREAM_TYPE) return "USE_DEFAULT_STREAM_TYPE";
         return "UNKNOWN_STREAM_" + stream;
diff --git a/media/java/android/media/audiopolicy/AudioProductStrategy.java b/media/java/android/media/audiopolicy/AudioProductStrategy.java
index 5d6ae5411b98..31d596765bcc 100644
--- a/media/java/android/media/audiopolicy/AudioProductStrategy.java
+++ b/media/java/android/media/audiopolicy/AudioProductStrategy.java
@@ -275,6 +275,7 @@ public final class AudioProductStrategy implements Parcelable {
      * @return the volume group id relevant for the given streamType.
      *         If none is found, {@link AudioVolumeGroup#DEFAULT_VOLUME_GROUP} is returned.
      */
+    @TestApi
     public int getVolumeGroupIdForLegacyStreamType(int streamType) {
         for (final AudioAttributesGroup aag : mAudioAttributesGroups) {
             if (aag.supportsStreamType(streamType)) {
@@ -355,10 +356,18 @@ public final class AudioProductStrategy implements Parcelable {
      * @hide
      * Default attributes, with default source to be aligned with native.
      */
-    public static final @NonNull AudioAttributes sDefaultAttributes =
+    private static final @NonNull AudioAttributes DEFAULT_ATTRIBUTES =
             new AudioAttributes.Builder().setCapturePreset(MediaRecorder.AudioSource.DEFAULT)
                                          .build();
 
+    /**
+     * @hide
+     */
+    @TestApi
+    public static @NonNull AudioAttributes getDefaultAttributes() {
+        return DEFAULT_ATTRIBUTES;
+    }
+
     /**
      * To avoid duplicating the logic in java and native, we shall make use of
      * native API native_get_product_strategies_from_audio_attributes
@@ -372,7 +381,7 @@ public final class AudioProductStrategy implements Parcelable {
         Preconditions.checkNotNull(attr, "attr must not be null");
         String refFormattedTags = TextUtils.join(";", refAttr.getTags());
         String cliFormattedTags = TextUtils.join(";", attr.getTags());
-        if (refAttr.equals(sDefaultAttributes)) {
+        if (refAttr.equals(DEFAULT_ATTRIBUTES)) {
             return false;
         }
         return ((refAttr.getSystemUsage() == AudioAttributes.USAGE_UNKNOWN)
diff --git a/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioManagerTest.java b/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioManagerTest.java
index 1131c623e428..27cf9434b34d 100644
--- a/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioManagerTest.java
+++ b/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioManagerTest.java
@@ -255,7 +255,7 @@ public class AudioManagerTest extends AudioVolumesTestBase {
         AudioVolumeGroupCallbackHelper vgCbReceiver = new AudioVolumeGroupCallbackHelper();
         mAudioManager.registerVolumeGroupCallback(mContext.getMainExecutor(), vgCbReceiver);
 
-        final List<Integer> publicStreams = Ints.asList(PUBLIC_STREAM_TYPES);
+        final List<Integer> publicStreams = Ints.asList(AudioManager.getPublicStreamTypes());
         try {
             // Validate Audio Volume Groups callback reception
             for (final AudioVolumeGroup audioVolumeGroup : audioVolumeGroups) {
diff --git a/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioProductStrategyTest.java b/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioProductStrategyTest.java
index c0f596b974e1..0e918d13e042 100644
--- a/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioProductStrategyTest.java
+++ b/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioProductStrategyTest.java
@@ -20,6 +20,7 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
 
 import android.media.AudioAttributes;
+import android.media.AudioManager;
 import android.media.AudioSystem;
 import android.media.audiopolicy.AudioProductStrategy;
 import android.media.audiopolicy.AudioVolumeGroup;
@@ -71,7 +72,7 @@ public class AudioProductStrategyTest extends AudioVolumesTestBase {
         assertNotNull(audioProductStrategies);
         assertTrue(audioProductStrategies.size() > 0);
 
-        for (final int streamType : PUBLIC_STREAM_TYPES) {
+        for (final int streamType : AudioManager.getPublicStreamTypes()) {
             AudioAttributes aaFromStreamType =
                     AudioProductStrategy.getAudioAttributesForStrategyWithLegacyStreamType(
                             streamType);
diff --git a/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioVolumesTestBase.java b/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioVolumesTestBase.java
index a17d65cf7376..b30ef307855d 100644
--- a/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioVolumesTestBase.java
+++ b/media/tests/AudioPolicyTest/src/com/android/audiopolicytest/AudioVolumesTestBase.java
@@ -37,15 +37,10 @@ public class AudioVolumesTestBase extends ActivityInstrumentationTestCase2<Audio
     // Default matches the invalid (empty) attributes from native.
     // The difference is the input source default which is not aligned between native and java
     public static final AudioAttributes sDefaultAttributes =
-            AudioProductStrategy.sDefaultAttributes;
+            AudioProductStrategy.getDefaultAttributes();
 
     public static final AudioAttributes sInvalidAttributes = new AudioAttributes.Builder().build();
 
-    public final int[] PUBLIC_STREAM_TYPES = { AudioManager.STREAM_VOICE_CALL,
-            AudioManager.STREAM_SYSTEM, AudioManager.STREAM_RING, AudioManager.STREAM_MUSIC,
-            AudioManager.STREAM_ALARM, AudioManager.STREAM_NOTIFICATION,
-            AudioManager.STREAM_DTMF,  AudioManager.STREAM_ACCESSIBILITY };
-
     public AudioVolumesTestBase() {
         super("com.android.audiopolicytest", AudioPolicyTest.class);
     }
@@ -63,7 +58,7 @@ public class AudioVolumesTestBase extends ActivityInstrumentationTestCase2<Audio
             }
             AudioAttributes avgAttributes = sDefaultAttributes;
             for (final AudioAttributes aa : avg.getAudioAttributes()) {
-                if (!aa.equals(AudioProductStrategy.sDefaultAttributes)) {
+                if (!aa.equals(AudioProductStrategy.getDefaultAttributes())) {
                     avgAttributes = aa;
                     break;
                 }
@@ -89,7 +84,7 @@ public class AudioVolumesTestBase extends ActivityInstrumentationTestCase2<Audio
                     assertTrue(!avg.getAudioAttributes().isEmpty());
                     AudioAttributes avgAttributes = sDefaultAttributes;
                     for (final AudioAttributes aa : avg.getAudioAttributes()) {
-                        if (!aa.equals(AudioProductStrategy.sDefaultAttributes)) {
+                        if (!aa.equals(AudioProductStrategy.getDefaultAttributes())) {
                             avgAttributes = aa;
                             break;
                         }
@@ -114,7 +109,7 @@ public class AudioVolumesTestBase extends ActivityInstrumentationTestCase2<Audio
 
         // Store the original volumes that that they can be recovered in tearDown().
         mOriginalStreamVolumes.clear();
-        for (int streamType : PUBLIC_STREAM_TYPES) {
+        for (int streamType : AudioManager.getPublicStreamTypes()) {
             mOriginalStreamVolumes.put(streamType, mAudioManager.getStreamVolume(streamType));
         }
         // Store the original volume per attributes so that they can be recovered in tearDown()
diff --git a/services/core/java/com/android/server/audio/AudioService.java b/services/core/java/com/android/server/audio/AudioService.java
index 148c72337be4..988e6f1efdc5 100644
--- a/services/core/java/com/android/server/audio/AudioService.java
+++ b/services/core/java/com/android/server/audio/AudioService.java
@@ -3470,7 +3470,7 @@ public class AudioService extends IAudioService.Stub
         }
         // The default volume group is the one hosted by default product strategy, i.e.
         // supporting Default Attributes
-        return getVolumeGroupIdForAttributesInt(AudioProductStrategy.sDefaultAttributes);
+        return getVolumeGroupIdForAttributesInt(AudioProductStrategy.getDefaultAttributes());
     }
 
     private int getVolumeGroupIdForAttributesInt(@NonNull AudioAttributes attributes) {
@@ -6162,7 +6162,7 @@ public class AudioService extends IAudioService.Stub
 
     private void ensureValidAttributes(AudioVolumeGroup avg) {
         boolean hasAtLeastOneValidAudioAttributes = avg.getAudioAttributes().stream()
-                .anyMatch(aa -> !aa.equals(AudioProductStrategy.sDefaultAttributes));
+                .anyMatch(aa -> !aa.equals(AudioProductStrategy.getDefaultAttributes()));
         if (!hasAtLeastOneValidAudioAttributes) {
             throw new IllegalArgumentException("Volume Group " + avg.name()
                     + " has no valid audio attributes");
@@ -6210,7 +6210,7 @@ public class AudioService extends IAudioService.Stub
         private int mIndexMax;
         private int mLegacyStreamType = AudioSystem.STREAM_DEFAULT;
         private int mPublicStreamType = AudioSystem.STREAM_MUSIC;
-        private AudioAttributes mAudioAttributes = AudioProductStrategy.sDefaultAttributes;
+        private AudioAttributes mAudioAttributes = AudioProductStrategy.getDefaultAttributes();
 
         // No API in AudioSystem to get a device from strategy or from attributes.
         // Need a valid public stream type to use current API getDeviceForStream
@@ -6223,8 +6223,9 @@ public class AudioService extends IAudioService.Stub
             if (DEBUG_VOL) {
                 Log.v(TAG, "VolumeGroupState for " + avg.toString());
             }
+            // mAudioAttributes is the default at this point
             for (final AudioAttributes aa : avg.getAudioAttributes()) {
-                if (!aa.equals(AudioProductStrategy.sDefaultAttributes)) {
+                if (!aa.equals(mAudioAttributes)) {
                     mAudioAttributes = aa;
                     break;
                 }