android: camera_stream: Retrieve Stream and Configuration

It's a common pattern to access the libcamera::Stream and
libcamera::StreamConfiguration using the CameraStream instance's
index.

Add two methods to the CameraStream to shorten access to the
two fields. This allows removing the index() method from the class
interface.

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

src/android/camera_stream.h

@@ -115,7 +115,9 @@ public:
 	const libcamera::PixelFormat &format() const { return format_; }
 	const libcamera::Size &size() const { return size_; }
 	Type type() const { return type_; }
-	unsigned int index() const { return index_; }
+
+	const libcamera::StreamConfiguration &configuration() const;
+	libcamera::Stream *stream() const;
 
 	int configure(const libcamera::StreamConfiguration &cfg);
 	int process(const libcamera::FrameBuffer &source,