Fix uncertainty of one normal mix buffer in AudioTrack::getTimestamp

The per-thread timestamp latch was not synchronized with the per-track
released frames.  Now the value of each track's released frames is
latched along with the timestamp.

Bug: 17531839
Bug: 17669342
Change-Id: I96252782911bd42a2534cc4030521b7eeb99a7b9
3 files changed