Fix sticky firstEventAfterDiscontinuity setting

This value needs to be explicitly set to false to prevent re-using a
stale "true" value.

Fixes: 245965753
Test: CTS SensorHeadTrackerTest#testDiscontinuity (pending upload)
Change-Id: Icd018e0cab9e30b0677970760a38a390d9dd2a3c

core/java/android/hardware/SystemSensorManager.java

@@ -882,6 +882,7 @@ public class SystemSensorManager extends SensorManager {
             }
 
             // Indicate if the discontinuity count changed
+            t.firstEventAfterDiscontinuity = false;
             if (t.sensor.getType() == Sensor.TYPE_HEAD_TRACKER) {
                 final int lastCount = mSensorDiscontinuityCounts.get(handle);
                 final int curCount = Float.floatToIntBits(values[6]);