Volume synchronisation consistently fails on Bluez >5.60
Please see https://github.com/bluez/bluez/issues/188
Aug 16 18:39:36 xps bluetoothd[16960]: profiles/audio/avctp.c:avctp_control_confirm() Control: Refusing unexpected connect
Aug 16 18:39:37 xps bluetoothd[16960]: profiles/audio/avctp.c:uinput_create() Can't open input device: No such file or directory (2)
Aug 16 18:39:37 xps bluetoothd[16960]: profiles/audio/avctp.c:init_uinput() AVRCP: failed to init uinput for GS