Remove isUnsafeBuild() from IpSecAlgorithm

IpSec is going to move to Connectivity mainline module so
hidden API usage should be removed. There's no formal API
could be an alternative for Build.IS_ENG. Considering
isUnsafeBuild() is not a really helpful method because it
only prints the log in eng build. Therefore, remove it.

Bug: 204153604
Test: FrameworksNetTests
Change-Id: Ic354e12423629b0d72e8087843893953a0c8c465

packages/ConnectivityT/framework-t/src/android/net/IpSecAlgorithm.java

@@ -469,20 +469,12 @@ public final class IpSecAlgorithm implements Parcelable {
         }
     }
 
-    // Because encryption keys are sensitive and userdebug builds are used by large user pools
-    // such as beta testers, we only allow sensitive info such as keys on eng builds.
-    private static boolean isUnsafeBuild() {
-        return Build.IS_DEBUGGABLE && Build.IS_ENG;
-    }
-
     @Override
     @NonNull
     public String toString() {
         return new StringBuilder()
                 .append("{mName=")
                 .append(mName)
-                .append(", mKey=")
-                .append(isUnsafeBuild() ? HexDump.toHexString(mKey) : "<hidden>")
                 .append(", mTruncLenBits=")
                 .append(mTruncLenBits)
                 .append("}")