Revert "Pass in active device to all BluetoothA2dp APIs in packa..."

Revert submission 10253996-bt-a2dp-no-null

Reason for revert: b/149361880
Reverted Changes:
If43934374: Pass in active device to all BluetoothA2dp APIs in...
I22dd1ca36: Make sure calls to BluetoothA2dp APIs pass non-nul...
If6475af6f: Require user pass in a non-null BluetoothDevice to...
I9d0e2c89c: Pass in active device to all BluetoothA2dp APIs in...
I1faa6174d: Need to now pass in active device instead of null ...
I69a941a7e: Pass in active device to all BluetoothA2dp APIs in...

Change-Id: I1d8660b11c917cf657e61478d58794182e17ec1a