diff --git a/media/java/android/media/MediaSession2.java b/media/java/android/media/MediaSession2.java
index e60c5f9b3b8ca..91bfacee97897 100644
--- a/media/java/android/media/MediaSession2.java
+++ b/media/java/android/media/MediaSession2.java
@@ -181,16 +181,6 @@ public class MediaSession2 implements AutoCloseable {
      */
     public static final int COMMAND_CODE_PLAYBACK_ADJUST_VOLUME = 11;
 
-    /**
-     * Command code for {@link MediaController2#setPlaylistParams(PlaylistParams)}.
-     * <p>
-     * Command would be sent directly to the player if the session doesn't reject the request
-     * through the {@link SessionCallback#onCommandRequest(MediaSession2, ControllerInfo, Command)}.
-     * @hide
-     */
-    // TODO(jaewan): Remove (b/74116823)
-    public static final int COMMAND_CODE_PLAYBACK_SET_PLAYLIST_PARAMS = 12;
-
     /**
      * Command code for {@link MediaController2#skipToPlaylistItem(MediaItem2)}.
      * <p>
@@ -313,6 +303,13 @@ public class MediaSession2 implements AutoCloseable {
      */
     public static final int COMMAND_CODE_PREPARE_FROM_SEARCH = 27;
 
+    /**
+     * Command code for {@link MediaController2#setRating(String, Rating2)}.
+     * @hide
+     */
+    // TODO(jaewan): Unhide
+    public static final int COMMAND_CODE_SET_RATING = 29;
+
     /**
      * Command code for {@link MediaBrowser2} specific functions that allows navigation and search
      * from the {@link MediaLibraryService2}. This would be ignored for a {@link MediaSession2},
@@ -322,11 +319,6 @@ public class MediaSession2 implements AutoCloseable {
      */
     public static final int COMMAND_CODE_BROWSER = 28;
 
-    /**
-     * @hide
-     */
-    public static final int COMMAND_CODE_MAX = 28;
-
     /**
      * @hide
      */
@@ -452,6 +444,13 @@ public class MediaSession2 implements AutoCloseable {
                     .createMediaSession2Command(this, COMMAND_CODE_CUSTOM, action, extras);
         }
 
+        /**
+         * @hide
+         */
+        public CommandProvider getProvider() {
+            return mProvider;
+        }
+
         public int getCommandCode() {
             return mProvider.getCommandCode_impl();
         }
@@ -510,6 +509,13 @@ public class MediaSession2 implements AutoCloseable {
                     .createMediaSession2CommandGroup(context, this, others);
         }
 
+        /**
+         * @hide
+         */
+        public CommandGroup(@NonNull CommandGroupProvider provider) {
+            mProvider = provider;
+        }
+
         public void addCommand(@NonNull Command command) {
             mProvider.addCommand_impl(command);
         }
@@ -622,7 +628,6 @@ public class MediaSession2 implements AutoCloseable {
          * @see #COMMAND_CODE_PLAYBACK_REWIND
          * @see #COMMAND_CODE_PLAYBACK_SEEK_TO
          * @see #COMMAND_CODE_PLAYLIST_SKIP_TO_PLAYLIST_ITEM
-         * @see #COMMAND_CODE_PLAYBACK_SET_PLAYLIST_PARAMS
          * @see #COMMAND_CODE_PLAYLIST_ADD_ITEM
          * @see #COMMAND_CODE_PLAYLIST_REMOVE_ITEM
          * @see #COMMAND_CODE_PLAYLIST_GET_LIST