frameworks/av: Fix a/v sync issue for playback over BT

-Audio and video are out of sync when a video is played/streamed
with a BT headset connected to the target.
-AudioTrack does not consider the BT latency.
-Latency of the BT stream added to the existing latency.

-query for tunnel mode latency
-During tunnel playback, we need to offset latency for audio plaback
 on BT devices by querying BT HAL.

Change-Id: I3142d8d70f1adaa6e7f5e37c812b13f69a84282a