Keep device from suspending when BT transfer is ongoing

This uses pm_stay_awake/pm_relax/etc. to prevent the device from
suspending when a BT transfer is happening (HOST_WAKE is asserted).
It also allows the device to auto-suspend to pm runtime only when there
are no transfer ongoing as well, meaning when HOST_WAKE is low.

Test: Manual
Bug: 189177739
Bug: 189370529

Signed-off-by: mullerf <mullerf@google.com>
Change-Id: Ia0f99683a08833e33422966e7bcf31c967e43a03
Signed-off-by: jonerlin <jonerlin@google.com>