android: camera_device: Cache request metadata

The settings in an android capture request may be null, in which case
the settings from the most recently submitted capture request should be
used. Cache the request settings to achieve this.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

src/android/camera_device.h

@@ -134,6 +134,8 @@ private:
 	int orientation_;
 
 	unsigned int maxJpegBufferSize_;
+
+	CameraMetadata lastSettings_;
 };
 
 #endif /* __ANDROID_CAMERA_DEVICE_H__ */