frameworks/av: Fix for audio playing on speaker when headset is
removed

- Currently LPA playback latency is set to zero. Because of this
  checkDeviceMuteStrategies() doesn't mute the stream while changing
  the devices. Hence music plays on speaker while device switch
  from headset to bluetooth.
- Set LPA plyback latency to 96ms as normal playback.

CRs-fixed: 417245
(cherry picked from commit 7108199eaa25afdf4ec29174147399664aa85d41)

Change-Id: I5798fb2b1163389e2afd21e34118a39492694a89