AudioManager: fix implementation of isMusicActive()

Implementation of isMusicActive() should go through AudioService
as AudioSystem.isStreamActive() can only be called from system
service.

Bug: 175084989
Bug: 162423060
Test: atest AudioManagerTest
Change-Id: I15b3f7cd082a7497f857e6bf261f933224da853e

media/java/android/media/AudioManager.java

@@ -2881,7 +2881,12 @@ public class AudioManager {
      * @return true if any music tracks are active.
      */
     public boolean isMusicActive() {
-        return AudioSystem.isStreamActive(STREAM_MUSIC, 0);
+        final IAudioService service = getService();
+        try {
+            return service.isMusicActive();
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
     }
 
     /**

media/java/android/media/IAudioService.aidl

@@ -334,4 +334,6 @@ interface IAudioService {
     oneway void setStreamVolumeForUid(int streamType, int direction, int flags,
             in String packageName, int uid, int pid, in UserHandle userHandle,
             int targetSdkVersion);
+
+    boolean isMusicActive();
 }

services/core/java/com/android/server/audio/AudioService.java

@@ -2108,6 +2108,12 @@ public class AudioService extends IAudioService.Stub
         return getDevicesForAttributesInt(attributes);
     }
 
+    /** @see AudioManager#isMusicActive() */
+    public boolean isMusicActive() {
+        // no permission required
+        return AudioSystem.isStreamActive(AudioSystem.STREAM_MUSIC, 0);
+    }
+
     protected @NonNull ArrayList<AudioDeviceAttributes> getDevicesForAttributesInt(
             @NonNull AudioAttributes attributes) {
         Objects.requireNonNull(attributes);