Annotations for Bluetooth broadcast intents.

Recent work has been using Error Prone rules and annotations to
reflect the current state of permission enforcement across the
Bluetooth stack, and we're now in a position were we can add new
permission enforcement that had been missing.

We've currently standardized on saying that APIs that return device
or Bluetooth state information (without sharing details about any
particular remote Bluetooth device) do not need to be permission
protected.

Bug: 183626724
Test: ./build/soong/soong_ui.bash --make-mode Bluetooth RUN_ERROR_PRONE=true
Change-Id: I53ac7a4fe1dea57316048c3cac4fa237b6ba3d38