Update MediaController comment to mention notification listeners

Forgot to update the comment to specify that notification listeners
may also get a MediaController from the manager.

Change-Id: Id38bcf7cb38185bfe4f99bcf8889a6415320dd36
diff --git a/media/java/android/media/session/MediaController.java b/media/java/android/media/session/MediaController.java
index 9641f83..12ee59e 100644
--- a/media/java/android/media/session/MediaController.java
+++ b/media/java/android/media/session/MediaController.java
@@ -47,8 +47,9 @@
  * receive updates from the session, such as metadata and play state changes.
  * <p>
  * A MediaController can be created through {@link MediaSessionManager} if you
- * hold the "android.permission.MEDIA_CONTENT_CONTROL" permission or directly if
- * you have a {@link MediaSession.Token} from the session owner.
+ * hold the "android.permission.MEDIA_CONTENT_CONTROL" permission or are an
+ * enabled notification listener or by getting a {@link MediaSession.Token}
+ * directly from the session owner.
  * <p>
  * MediaController objects are thread-safe.
  */