aaudio: implement native IPLayer for legacy playback streams

Make AudioStreamTrack derive from PlayerTrackBase to
provide playback and volume control via IPLayer interface.

Bug: 62027849
Test: verify aaudio playback regressions and registration of aaudio
players in AudioService

Change-Id: I5c04110f1554233eae3f1bc357a64a584d7303d1
diff --git a/media/libaaudio/src/legacy/AudioStreamTrack.h b/media/libaaudio/src/legacy/AudioStreamTrack.h
index 990f005..ff429ea 100644
--- a/media/libaaudio/src/legacy/AudioStreamTrack.h
+++ b/media/libaaudio/src/legacy/AudioStreamTrack.h
@@ -18,7 +18,7 @@
 #define LEGACY_AUDIO_STREAM_TRACK_H
 
 #include <math.h>
-#include <media/AudioTrack.h>
+#include <media/TrackPlayerBase.h>
 #include <aaudio/AAudio.h>
 
 #include "AudioStreamBuilder.h"
@@ -32,7 +32,7 @@
 /**
  * Internal stream that uses the legacy AudioTrack path.
  */
-class AudioStreamTrack : public AudioStreamLegacy {
+class AudioStreamTrack : public AudioStreamLegacy, public android::TrackPlayerBase {
 public:
     AudioStreamTrack();
 
@@ -78,7 +78,6 @@
 
 private:
 
-    android::sp<android::AudioTrack> mAudioTrack;
     // adapts between variable sized blocks and fixed size blocks
     FixedBlockReader                 mFixedBlockReader;