The service is supposed to regenerate the catalog index whenever /usr is
updated, but /var is not. Hence the ConditionNeedsUpdate= line should
actually reference /var, as that's where the index file is located.
Services which are not crucial to system bootup, and have Type=oneshot
can effectively "hang" the system if they fail to complete for whatever
reason. To allow the boot to continue, kill them after a timeout.
In case of systemd-journal-flush the flush will continue in the background,
and in the other two cases the job will be aborted, but this should not
result in any permanent problem.
The only update service we really need to guard like this is
systemd-tmpfiles-setup.service since if invoked manually might create
/var/run/nologin and thus blocking the user from login. The other
services are pretty much idempotent and don't suffer by this problem,
hence let's simplify them.
