Only restart bluetooth if INIT_FLAGS have changed

Otherwise we keep restarting it randomly, especially for dogfooders, and
not everything likes it when Bluetooth restarts (especially if they're
doing LE stuff in the background).

Test: atest BluetoothDeviceConfigChangeTrackerTest and manually changing
flags with adb
Tag: #stability
Bug: 242348618

Change-Id: Ia955e5ed92c51ec65e0ac0dc42e0998b9c9845ae