audio_policy: Fix for audio routing speaker though BT is connected

- Speaker device is selected by getDeviceForStrategy() though BT is
  connected as mA2dpSuspended is still remaining as 'true' even
  after ending the voice call.
- This flasg is not updated by checkA2dpSuspend() as force usage
  for communication and record is still FORCE_BT_SCO after ending
  voice call.
- Modified condition check to set mA2dpSuspended to 'false' as soon
  as phone state is changed to MODE_NORMAL
  porting from change:Ib3a67268be33a10c6bcdf6437868990a92a06c2f

Change-Id: I86ebb66cd165e8009bfa6193d2ad9ab383996283
CRs-Fixed: 671810