Camera2: Listener rework and other API updates

 - Add Handlers to each callback-accepting function
 - Expand CameraDevice ErrorListener to CameraDeviceListener
   - Add idle callback
   - Split out disconnect error to its own callback
 - Add CameraDevice#getId
 - Rename CameraManager's listener to AvailabilityListener
 - Rename CameraManager register/unregister*Listener to
   add/remove*Listener
 - Rename getDeviceIdList to getCameraIdList

Bug: 10549567
Bug: 10549462
Change-Id: Idd2ae8ad8eb126f35a15d765306ada7c1cf74eea