AudioTrack: Fix for offload to BT/SSR fallback at EOS

 -With big offload buffer size, connect BT or trigger SSR
  while waiting for stream to be completed, playback is
  moving to next clip.

 -avoid notifying EOS to client on any error while waiting for
  stream end event if it is offload playback.

Change-Id: I748ed299df106385eaa030faecd0df6dc8e3c176