User switch: Unbind headsetservice in bluetooth Off state.

Usecase:
Do user switch continuosly multiple times.

Expectation:
Auto connect must happen and settings UI should display it.

observed Result:
Auto-connection on headset profile is success,
but settings UI is not displaying it as connected.

Root Cause:
Handler not able to process state change messages in User switch
scenario, hence bluetoothstatechange call back not updated to
headset service , headset connection state not reflecting in UI

Fix:
Made changes in handler to send bluetoothstatechange call back
in bluetooth off state.

CRs-Fixed: 2685994
Change-Id: I0fccff89beb29bd1ebf236ef8edfc25cb493f614