Implement setting/getting whether audio can be routed to the HFP HF device. am: 22bb394443 am: c3da0f7bb3
am: 80ebb2a7df

* commit '80ebb2a7dfb1aa1cd44f06d989801b628e138f98':
  Implement setting/getting whether audio can be routed to the HFP HF device.