initrd: make udev cleanup service confict trigger and settle too

Otherwise, systemd-udev-trigger|settle.service that ran in the initrd may
ramain active, and never re-run again from the system root.

This is observed by forexample examining ESP with udevadm info, which in the
initrd has all the ID_* variables, and none of them in fully booted system.

(cherry picked from commit f27bb6ab)
(cherry picked from commit 946cdba1)