Fix output switcher will show 2 media sessions in some use cases

Before this CL, we didn't check whether the remote session existed
in the list before. If the priority of a remote session is higher than
a local session, it causes us to return the local session even if
the list has a remote session.

This CL uses a list to cache package names of remote sessions.
If the local session has the same package name of the remote session
then don't return the local session.

Bug: 169052790
Test: make -j42 RunSettingsRoboTests
Change-Id: I2726a3deb397f646e4c74a8c445dde6fafb694a8
Merged-In: I2726a3deb397f646e4c74a8c445dde6fafb694a8
(cherry picked from commit 3a7293cbbf)

src/com/android/settings/media/MediaOutputUtils.java

@@ -25,6 +25,9 @@ import androidx.annotation.Nullable;
 
 import com.android.settings.sound.MediaOutputPreferenceController;
 
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * Utilities that can be shared between {@link MediaOutputIndicatorWorker} and
  * {@link MediaOutputPreferenceController}.
@@ -43,6 +46,7 @@ public class MediaOutputUtils {
             MediaSessionManager mediaSessionManager) {
 
         MediaController localController = null;
+        final List<String> remoteMediaSessionLists = new ArrayList<>();
         for (MediaController controller : mediaSessionManager.getActiveSessions(null)) {
             final MediaController.PlaybackInfo pi = controller.getPlaybackInfo();
             if (pi == null) {
@@ -69,10 +73,14 @@ public class MediaOutputUtils {
                         controller.getPackageName())) {
                     localController = null;
                 }
+                if (!remoteMediaSessionLists.contains(controller.getPackageName())) {
+                    remoteMediaSessionLists.add(controller.getPackageName());
+                }
                 continue;
             }
             if (pi.getPlaybackType() == MediaController.PlaybackInfo.PLAYBACK_TYPE_LOCAL) {
-                if (localController == null) {
+                if (localController == null
+                        && !remoteMediaSessionLists.contains(controller.getPackageName())) {
                     localController = controller;
                 }
             }

tests/robotests/src/com/android/settings/media/MediaOutputUtilsTest.java

@@ -115,6 +115,33 @@ public class MediaOutputUtilsTest {
 
     @Test
     public void getActiveLocalMediaController_bothHaveRemoteMediaAndLocalMedia_returnNull() {
+        mMediaControllers.clear();
+        final MediaController.PlaybackInfo playbackInfo = new MediaController.PlaybackInfo(
+                MediaController.PlaybackInfo.PLAYBACK_TYPE_REMOTE,
+                VolumeProvider.VOLUME_CONTROL_ABSOLUTE,
+                100,
+                10,
+                new AudioAttributes.Builder().setUsage(AudioAttributes.USAGE_MEDIA).build(),
+                null);
+        final PlaybackState playbackState = new PlaybackState.Builder()
+                .setState(PlaybackState.STATE_PLAYING, 0, 1)
+                .build();
+        final MediaController remoteMediaController = mock(MediaController.class);
+
+        mMediaControllers.add(remoteMediaController);
+        mMediaControllers.add(mMediaController);
+        initPlayback();
+
+        when(mMediaController.getPlaybackInfo()).thenReturn(mPlaybackInfo);
+        when(mMediaController.getPlaybackState()).thenReturn(mPlaybackState);
+        when(remoteMediaController.getPlaybackInfo()).thenReturn(playbackInfo);
+        when(remoteMediaController.getPlaybackState()).thenReturn(playbackState);
+
+        assertThat(MediaOutputUtils.getActiveLocalMediaController(mMediaSessionManager)).isNull();
+    }
+
+    @Test
+    public void getActiveLocalMediaController_bothHaveLocalMediaAndRemoteMedia_returnNull() {
         final MediaController.PlaybackInfo playbackInfo = new MediaController.PlaybackInfo(
                 MediaController.PlaybackInfo.PLAYBACK_TYPE_REMOTE,
                 VolumeProvider.VOLUME_CONTROL_ABSOLUTE,