So I'm currently not in a GNOME session to test, but it looks like that should be fixed by adjusting the standard package selection for the GNOME desktop in Solus. Unless something else is going on here.
You could try install rygel and/or gnome-user-share and see if it fixes that menu for you. If not, then something is probably off with the gnome-control-center package, and you can't fix that yourself (without getting into Solus packaging, that is)