AudioDeviceRegistry component. The AudioDeviceRegistry can request that we
start and/or stop the audio in-band which will send the request on to the
HFP task to initiate Audio Connection Setup when no call is in progress.
A Control that either sends the audio directly to the controller (using an offload
Control) or encodes audio locally and sends it in the SCO channel, depending on
whether the codec is in the list of offload-supported codecs.