Since we don't run preset-all on the test image, the
systemd-userdbd.socket remains disabled. Let's pull it in explicitly
to give systemd-userdbd some coverage as well.
Those are all consumed by our parser, so they all support comments.
I was considering whether they should have a license header at all,
but in the end I decided to add it because those files are often created
by copying parts of real unit files. And if the real ones have a license,
then those might as well. It's easier to add it than to make an exception.
Frantisek Sumsal
Zbigniew Jędrzejewski-Szmek