Bluetooth: GAP: Cancel the pairing notification on bond state change

Cancel the pairing notification on bond state change happens from
BOND_BONDING to BOND_NONE.  Otherwise it will present in the
notification area until it gets cancelled by opening it and press
cancel on pairing dialog.

Change-Id: I96f673e29e612cd748165a1323a5b4a4276a843c
CRs-Fixed: 569534