Comment 4 for bug 1854379

This source field is only shown if the same app (as determined by AppStream ID) is available from multiple sources (e.g. a Snap and a Flatpak). In the case of snaps it wasn't showing because we haven't set the "origin_hostname" field. https://gitlab.gnome.org/GNOME/gnome-software/merge_requests/374 proposes falling back to the "origin" field (set to "Snap Store" for snaps.

We may also want to set the origin_hostname for snaps (to "snapcraft.io"?) but this seems less readable than Snap Store.