bluetooth: acquire wakelock when connection is complete

Acquire a wakelock when receving a connection request during system
suspend. Wait for a timeout to release the wakelock, so the bluetooth
device has time to send input events and wake up the system. If
bluetooth resumes first, also release the wakelock. The timeout is
defined with sysprop. If the timeout is zero, the request for wakelock
is ignored.

Bug: 369686962
Bug: 366432079
Test: m -j, suspend system and wake up with mouse
Flag: adapter_suspend_mgmt
Change-Id: Ia6aab33857d4d7a2ddc7c5ff8e182ab42cb77825