android: camera_device: Add buffers for each stream to Requests

Construct a FrameBuffer for every buffer given in the camera3Request
and add it to the libcamera Request on the appropriate stream.

The correct stream is obtained from the private data of the camera3_stream
associated with the camera3_buffer.

Comments regarding supporting only one buffer are now removed, and
FrameBuffers have their lifetime tracked in the Camera3RequestDescriptor
to ensure they are released when the Request is completed.

Signed-off-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.h

@@ -70,6 +70,7 @@ private:
 		uint32_t frameNumber;
 		uint32_t numBuffers;
 		camera3_stream_buffer_t *buffers;
+		std::vector<std::unique_ptr<libcamera::FrameBuffer>> frameBuffers;
 	};
 
 	struct Camera3StreamConfiguration {