We want that systemd --user gets its own keyring as usual, even if the
barebones PAM snippet we ship upstream is used. If we don't do this we get the
basic keyring systemd --system sets up for us.
It is impossible to ship a fully generic PAM configuration upstream.
Therefore, ship a minimal configuration with the systemd --user requirements,
and add a note to DISTRO_PORTING documenting this.
Fixes#4284
This way the user service will have a loginuid, and it will be inherited by
child services. This shouldn't change anything as far as systemd itself is
concerned, but is nice for various services spawned from by systemd --user
that expect a loginuid.
pam_loginuid(8) says that it should be enabled for "..., crond and atd".
user@.service should behave similarly to those two as far as audit is
concerned.
https://bugzilla.redhat.com/show_bug.cgi?id=1328947#c28