DO NOT MERGE trouble syncing with fitbit and can't turn off bluetooth.

this is to work around broadcom firmware problem to handle
unsolicited command complete event for HCI_LE_Create_Connection_Cancel
and LE connection complete event with status error code (0x2)
unknown connection identifier from bluetooth controller
the workaround is to release the HCI connection to avoid out of sync
with bluetooth controller, which cause BT can't be turned off.

bug:11614046
Change-Id: Ia5c5ad0c6c9b1a4f03253cac8a7caaf21341c88c