Add initialize method to CameraHardwareInterface

Add intialize() method to CameraHardwareInterface so we can
return a proper error value to CameraService if open of camera
hardware module fails.

b/5405235

Change-Id: I09c627034ddd22a5753c5163392c4fcff301e0b9
Signed-off-by: Tyler Luu <tluu@ti.com>
Signed-off-by: Iliyan Malchev <malchev@google.com>