AML: Use config_mediaMetadataBitmapMaxSize which is @SystemApi

Bug: 119749798
Test: mmm . (under frameworks/av/packages/MediaComponents)
Change-Id: Ib4f46c9adb61f6d6bdacdba43e706c8a1a735ab1
diff --git a/packages/MediaComponents/apex/java/android/media/session/MediaSession.java b/packages/MediaComponents/apex/java/android/media/session/MediaSession.java
index b40e3b0..deb0203 100644
--- a/packages/MediaComponents/apex/java/android/media/session/MediaSession.java
+++ b/packages/MediaComponents/apex/java/android/media/session/MediaSession.java
@@ -171,10 +171,8 @@
         if (TextUtils.isEmpty(tag)) {
             throw new IllegalArgumentException("tag cannot be null or empty");
         }
-        //TODO(b/119749798): Resolve hidden API usage. com.android.internal.R
-        //mMaxBitmapSize = context.getResources().getDimensionPixelSize(
-                //com.android.internal.R.dimen.config_mediaMetadataBitmapMaxSize);
-        mMaxBitmapSize = 1024;  //TODO: remove this.
+        mMaxBitmapSize = context.getResources().getDimensionPixelSize(
+                android.R.dimen.config_mediaMetadataBitmapMaxSize);
         mCbStub = new CallbackStub(this);
         MediaSessionManager manager = (MediaSessionManager) context
                 .getSystemService(Context.MEDIA_SESSION_SERVICE);