MediaPlayerService: avoid invalid static cast am: ee0a0e39ac am: 7b6a85546c am: b07255f603 am: d560830823 am: 51efd24460 am: 8d32201d4a am: 2b5ee9c8e4 am: 17744ab9d7 am: 77da9683de am: 739ce899e5 am: 19f10153d7
am: 949cf2bd84

Change-Id: I7dd421af9d3aee9292ea62019c4abeaa87a17b74