Fedora Silverblue upgrade via cockpit-ostree falsely shows removal of all overlays

[shdwchn10]

I can reproduce it with Fedora Silverblue 35 and 36

Maybe related #255

[garrett]

@martinpitt: My guess is that cockpit-ostree deploys the commit when clicking the "update and reboot" button, which (I think?) is correct when a local commit with overlays exists, but incorrect when something hasn't been deployed yet (as it won't actually upgrade but just deploy the remote commit without local changes).

[shdwchn10]

Yes, I tested upgrade in VM and can confirm that it's only a visual bug. Overlays still persist after upgrade via cockpit-ostree