fedora-remote: install Flatpaks system-wide on first boot

Per-user Flatpaks are only visible to the account that logged in first (and
consumed space per user). Install them into the system installation instead, so
every user including Kanidm accounts sees Firefox.

images/fedora-remote/custom.yaml

@@ -41,10 +41,10 @@ exclude-packages:
   - firefox
 
 add-files:
-  # Per-user Flatpaks on first login (Firefox).
-  - ["flatpak-user-firstboot", "/usr/libexec/flatpak-user-firstboot"]
-  - ["flatpak-user-firstboot.service", "/usr/lib/systemd/user/flatpak-user-firstboot.service"]
-  - ["60-flatpak-user-firstboot.preset", "/usr/lib/systemd/user-preset/60-flatpak-user-firstboot.preset"]
+  # System-wide Flatpaks on first boot (Firefox), visible to every user.
+  - ["flatpak-system-firstboot", "/usr/libexec/flatpak-system-firstboot"]
+  - ["flatpak-system-firstboot.service", "/usr/lib/systemd/system/flatpak-system-firstboot.service"]
+  - ["50-flatpak-system-firstboot.preset", "/usr/lib/systemd/system-preset/50-flatpak-system-firstboot.preset"]
   - ["flatpaks.list", "/usr/share/flatpak/flatpaks.list"]
   # Kanidm client config + authselect profile sources.
   - ["kanidm-config", "/etc/kanidm/config"]
@@ -107,5 +107,5 @@ postprocess:
   - |
     #!/usr/bin/env bash
     set -xeuo pipefail
-    chmod 0755 /usr/libexec/flatpak-user-firstboot /usr/libexec/grd-firstboot
+    chmod 0755 /usr/libexec/flatpak-system-firstboot /usr/libexec/grd-firstboot
     systemctl --user --global preset-all