android: camera_device: Provide a toPixelFormat helper

Rather than converting pixelformats through the map, and then
dereferencing the iterator later, create a helper to explicitly return a
PixelFormat type.

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

src/android/camera_device.h

@@ -72,6 +72,7 @@ private:
 	std::tuple<uint32_t, uint32_t> calculateStaticMetadataSize();
 	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
 	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
+	libcamera::PixelFormat toPixelFormat(int format);
 	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
 							  int64_t timestamp);