PAN: Notify PAN devices connection state to UI

Usecase:
1) Try to connect to remote device (where tethering is disabled)
2) Perform BT on off whiel above is ongoing

Expected Beahviour
UI shows correct status as connected/disconnected based on device is connected or
disconnected with remote device

Observed Result
DUT UI shows connected, even when remote device is not connected with DUT

Root Cause:
BluetoothPan.ACTION_CONNECTION_STATE_CHANGED is not broadcasted when BT is turned off
while Pan state is Connecting

Fix:
1) Notify PAN devices connection state to UI during BT turn off.
2) Update proper role during handlePanDeviceStateChange so as to stop Tethering or
   Reverse Tethering as the case may be during BT off time if enabled.

Test: UI is informed of PAN connection status during BT turning off state as well

Fixes: 73018139
Change-Id: I4b1413d68418c6675b8638d3f14e04aece84d3d4