Bluetooth: fix issues re-enabling after crash

When Bluetooth crashes, sometimes an LE app restarts it before
ActivityManager gets a chance.  In this case, the Bluetooth manager
would assume the state should be LE only and did not continue to fully
enabled.

Luckily in this case the persisted system state is also ON.  Use the
persisted state as information about whether we should be fully enabled.

Test: basic sanity check, forced crash of BT
Bug: 33632976
Change-Id: I546d7abccb82a26fcca2eb70d6d7c76e9510404e