Fix NotificationPlayer wakelock being held for too long.

We added a try/finally to the run() method, to make sure the wakelock gets released even if there was a crash. We also added a couple of try/catch blocks to log any issues releasing the MediaPlayer and abandoning audio focus.

Fix: 293371948
Test: N/A
Change-Id: Idfa4049b70ceb1bbdb5afce8f1cc8381796d6bbe