audioflinger: Ensure SRS effects are applied on active tracks

- When device is switched from BT to wired headset
  without disconnecting BT, SRS effects are not applied
  on wired headset
- Currently SRS module is checking for connected BT
  device and overriding the updated device from framework,
  with BT if BT device is connected
- call the API which will tell SRS module not to
  override the updated device from framework, irrespective
  BT device is connected or not, also while calling SRS API
  from mixer thread check if the track is active

CRs-Fixed: 640351

Change-Id: Ia96d0721d1811f18dbcfc08d96c5f1931359191a