mfvideosrc: Select common formats if both VideoPreview and VideoRecord are available
Some devices (e.g., Surface Book 2, Surface Pro X) will expose
both MediaStreamType_VideoPreview and MediaStreamType_VideoRecord types
for a logical device. And for some reason, MediaStreamType_VideoPreview
seems to be selected between them while initiailzing device.
But I cannot find any documentation for the decision rule.
To be safe, we will select common formats between them.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1478>