Bring Telecom logic into agreement with Bluetooth

Account for the BT active device being null sometimes (and not starting
calls on BT when so)
Follow the BT stack's changes on the BT active device

Fixes: 79231275
Test: unit, manual, BT team's regression suite

Change-Id: Ib6ced6baa9e0ca5fa17b854ae58f19e9d49a80fd
Merged-In: Ib6ced6baa9e0ca5fa17b854ae58f19e9d49a80fd
10 files changed