Set METADATA_KEY_TITLE

Issue: #4292

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=199478946

RELEASENOTES.md

@@ -10,6 +10,8 @@
   changes ([#4276](https://github.com/google/ExoPlayer/issues/4276)).
 * Fix `MediaCodec.native_setSurface` crash on Moto C
   ([#4315](https://github.com/google/ExoPlayer/issues/4315)).
+* Set `METADATA_KEY_TITLE` on media descriptions
+  ((#4292)[https://github.com/google/ExoPlayer/issues/4292]).
 
 ### 2.8.1 ###
 

extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java

@@ -600,8 +600,9 @@ public final class MediaSessionConnector {
               }
             }
             if (description.getTitle() != null) {
-              builder.putString(MediaMetadataCompat.METADATA_KEY_DISPLAY_TITLE,
-                  String.valueOf(description.getTitle()));
+              String title = String.valueOf(description.getTitle());
+              builder.putString(MediaMetadataCompat.METADATA_KEY_TITLE, title);
+              builder.putString(MediaMetadataCompat.METADATA_KEY_DISPLAY_TITLE, title);
             }
             if (description.getSubtitle() != null) {
               builder.putString(MediaMetadataCompat.METADATA_KEY_DISPLAY_SUBTITLE,