android: camera_device: Set the camera location to Front if External

Our android HAL implementation currently does not support external
cameras, so if the camera location property is external, set it to
front.

This allows the following CTS test to pass:
- android.hardware.camera2.cts.CameraManagerTest#testCameraManagerGetDeviceIdList

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

src/android/camera_device.cpp

@@ -405,7 +405,11 @@ int CameraDevice::initialize()
 			facing_ = CAMERA_FACING_BACK;
 			break;
 		case properties::CameraLocationExternal:
-			facing_ = CAMERA_FACING_EXTERNAL;
+			/*
+			 * \todo Set this to EXTERNAL once we support
+			 * HARDWARE_LEVEL_EXTERNAL
+			 */
+			facing_ = CAMERA_FACING_FRONT;
 			break;
 		}
 	}