floss: Append remote device name

Append the remote device name to OnBluetoothAudioDeviceAdded. This
requires bluetooth_media to access the bluetooth adapter interface. Thus
add a set_adapter function.

Tag: #floss
Bug: 227245776
Test: build,deploy,check dbus_monitor for the OnBluetoothAudioDeviceAdded
BYPASS_LONG_LINES_REASON: Bluetooth likes 120 char lines

Change-Id: I98251bab96ea296c2f011caf78d531af72780107