android: camera_device: Break-out request template

Currently the request template returned from
CameraDevice::constructDefaultRequestSettings() is the same for all
the supported template types.

To prepare to adjust the template depending on the use case, break out
the template generation to a dedicated function that supports the
PREVIEW use case. All the other template types use the
requestTemplatePreview() function and just update the capture intent
property.

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

src/android/camera_device.h

@@ -83,6 +83,7 @@ private:
 	libcamera::FrameBuffer *createFrameBuffer(const buffer_handle_t camera3buffer);
 	void notifyShutter(uint32_t frameNumber, uint64_t timestamp);
 	void notifyError(uint32_t frameNumber, camera3_stream_t *stream);
+	CameraMetadata *requestTemplatePreview();
 	libcamera::PixelFormat toPixelFormat(int format);
 	std::unique_ptr<CameraMetadata> getResultMetadata(int frame_number,
 							  int64_t timestamp);