MediaSession2: Avoid using package-private methods in *Compat

package-private method in dejetified code is not accessible
in androidx code.

Bug: 77932057
Test: ./gradlew :media:check
Change-Id: I5c399e73ca3e9dd63a5c10dfb8eed0e8a7804579
diff --git a/media/src/main/java/androidx/media/MediaBrowserServiceCompat.java b/media/src/main/java/androidx/media/MediaBrowserServiceCompat.java
index 430913e..8f24837 100644
--- a/media/src/main/java/androidx/media/MediaBrowserServiceCompat.java
+++ b/media/src/main/java/androidx/media/MediaBrowserServiceCompat.java
@@ -1020,8 +1020,11 @@
      * Note that we cannot simply override {@link Service#attachBaseContext(Context)} and hide it
      * because lint checks considers the overriden method as the new public API that needs update
      * of current.txt.
+     *
+     * @hide
      */
-    void attachToBaseContext(Context base) {
+    @RestrictTo(LIBRARY)
+    public void attachToBaseContext(Context base) {
         attachBaseContext(base);
     }