Revert "Revert "Refactor ProximityUpdateCallbackInternal to inte..."

Revert submission 19600381-revert-17936037-hotword_proximity-ZZIDPDULZP

Test: atest CtsVoiceInteractionTestCases, atest CtsVoiceInteractionTestCases:android.voiceinteraction.cts.AlwaysOnHotwordDetectorTest#testAlwaysOnHotwordDetector_startRecognitionWithData -- --abi x86_64
Reason for revert: Including the fix for broken tests
Reverted Changes:
Ibfc659015:Revert "Refactor ProximityUpdateCallbackInternal t...
I1a03c21d5:Revert "Verify that proximity key is added to the ...
I6b79d9400:Revert "Add proximity state to the HotwordDetected...

Change-Id: Iee6ab086ccc3f27b95ee601d6be11231f300170c