In the context of INSTALLER-4416 a proof of concept made the integration possible (https://github.com/rhinstaller/anaconda/pull/6690). The goal of this story is to stabilise the PoC to have something production ready and fix its issues.

The main issues that need to be fixed on the PoC are:

• Improve code organisation/readability
• Remove the hardcoded value from `DNFManager.get_flatpak_refs`
• Alter flatpak configuration on-the-fly -> replace registry with satellite's when required
• Setup flatpak authentication post installation

Acceptance criteria

• When the package `redhat-flatpak-preinstall-firefox` (or any equivalent flatpak-preinstall pkg is present), the flatpak must be installed from satellite's flatpak registry, ignoring the package original configuration.
• After installation, it should be possible to install other flatpaks from that registry without extra configuration.