CameraService: Clean up ICameraServiceProxy; send it more info

- Remove hand-written ICameraServiceProxy C++ impl; use the AIDL-
  generated version instead
- Send client package name and camera facing with the camera state
  notices

Test: Verify by logging that information sent to proxy is correct;
      no camera CTS regressions.
Bug: 32449509
Change-Id: I7a305b76b4f1d5c08b7938108bd73c95986508e0