Join HandlerThread if BLE is not supported

Unfortunately, in order to make the Handler constructor happy,
HandlerThread does need to be started briefly (to return a Looper
object). However, is BLE is not supported, there is no need to leave the
thread running.

Test: TH
Change-Id: I47e455544aa40654676c4154a5e28a52d1c6c05b
1 file changed