Bluetooth: Update SCAN MODE state while turn OFF Bluetooth

Change will update SCAN MODE state while turn OFF Bluetooth, since
Bluetooth application is expecting adapterPropertyChangedCallback
while turning OFF BT. Otherwise, while Bluetooth is turning OFF
SET_SCAN_MODE_TIMEOUT occurs and application will not get proper
callback.

CRs-Fixed: 550485
Change-Id: I8bfdbdbf1962aff04cd7fdb4cee67d639bed8a38