libstagefright: Handle INFO_FORMAT_CHANGED for dolby clips

  -For dolby clips when device is switched from headset to
   BT multiple times, media error is observed, and playback
   stops
  -When end device is changed, s/w Dolby decoder generates
   format change event which in certain condition leads to
   media error and playback stops
  -Make sure format change error is handled in AudioPlayer
   layer

CRs-Fixed: 706801

Change-Id: I3ff3ef84b15ea5f9d3288215c1491dc30d17a413