Handle UID state change on separate thread

UID changes are dispatched on the UI thread, so to avoid blocking in the
case that we have mutex contention due to a slow sensor HAL, queue
updates for deferred process on SensorService's looper (aka
SensorEventAckReceiver).

Bug: 399607981
Test: monitor typical UID state changes with extra debug logs
Test: manually trigger UID state changes and confirm functionality
Flag: com.android.frameworks.sensorservice.flags.use_looper_for_uid_state_change
Change-Id: I4478a628ecfc578ba6ffe5ec85a7882df8deaed4