Cannot play mp4 file which contains ac-3

Problem: ac-3 bit stream identification parse error
Solution: skip audio track if ac-3 is not correct

Bug: 122746530
Test: Play the video file whose ac-3 is not correct
and check if it can skip audio and only play video
track

Change-Id: I402781a9d7057fd24666652b015d25cc11efa7bd