Camera: Rename new API to camera2, rearrange camera service

 - Support API rename from photography to camera2
 - Reorganize camera service files
   - API support files to api1/, api2/, api_pro/
   - HAL device support files into device{1,2,3}/
   - Common files into common/
   - Camera service remains at top-level

Change-Id: Ie474c12536f543832fba0a2dc936ac4fd39fe6a9