Refactor sensor use dialog to show above applications

Prevent overlays on the sensor use dialog (tv)

Test: atest CtsSensorPrivacyTestCases
      Manual; tested basic cases, tested apps or the assistant can't
              draw over, tested dialog works on lock screen correctly,
	      tested dialog works correclty when screen orientation is
	      changed.
Fixes: 195376319
Bug: 199550934
Change-Id: Iddfbbe8692c4c0293c73abd2cf4fc0ee947892ca