Update usage of A2dpService API calls that take BluetoothDevice as an additional argument. If the BluetoothDevice argument is null, the API applies to the device that is currently the Active A2DP device. Exempt-From-Owner-Approval: De-facto owner of the relevant changes is the Bluetooth team. Bug: 69269748 Test: Manual Change-Id: I7417b7b0741f706df475cb2b27fbe6525f744269