Comment 26 for bug 1574045

Ok, turns out this actually breaks everything as the provider
id needs to match the filename.

So we've brainstormed this with Alberto again and we have
a better solution, which will involve a patch to libaccounts-glib
to look into /usr/share/accounts/{providers, services}/$XDG_CURRENT_DESKTOP/*
with /usr/share/accounts/{providers, services}/* as a fallback.

This way we can install our files into special directory without
needing any new env vars and/or changes in AppArmor and/or
needing to rename anything. All this will need is a new release
of libaccounts-glib.

I'll keep this bug updated.