Scan manager: Suspend scan when location is off

* Add a broadcast receiver to listen for location on/off event. When
location is off, send SUSPEND_SCAN message; when location is on, send
RESUME_SCAN message
* In handleStartScan(), suspend the scan if location is off, unless it
is a filtered scan or issued by a legacy app
* Both location on/off and display on/off events are handled in
HandlerThread, so there is no collision
* Add instrumentation test to bring GattService up and down

Test: instrumentation test and manual
Bug: 73485839
Change-Id: I3230ccd6406733043611406d3f19e99863ff082e