Bluetooth: Acquire wakelock to turn on lcd during Connection

This patch acquires wakelock to turn on LCD display of DUT if screen
is off during connection access request for PBAP/MAP. Without this
patch it was observed that if screen was off, lcd remained off for
incoming connection access request from remote device and user only
was hearing notification sound without lcd being lit up.

Change-Id: I87c296fce4cd8e0c133f74169d991eee263fed08
CRs-Fixed: 650261
Bluetooth: Fix for device gets stuck in pairing

Fix for device gets stuck in pairing when trying to pair to two
devices one after the other or simultaneous. Now second pairing
is blocked when first pairing is ongoing.

Change-Id: Ib7e6788243a38b3a0dd864bee2b0797305468e27
CRs-fixed: 610056