Camera: Add onCameraOpened/onCameraClosed callbacks

The onCameraOpened/onCameraClosed callbacks are used to notify camera
service client with [] permission that a certain camera device has been
opened/closed.

Test: Manually check callbacks are received in SystemUI app
Bug: 150540299
Change-Id: If6f3624c43927c30afef7df0a780eafe3ae4c527
Merged-In: If6f3624c43927c30afef7df0a780eafe3ae4c527
6 files changed