/usr/lib/systemd/user/ is in unity-services 7.5.0+18.04.20180413-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/systemd/user/unity-panel-service-lockscreen.service
/usr/lib/systemd/user/unity-panel-service-lockscreen.service.wants/
/usr/lib/systemd/user/unity-panel-service-lockscreen.service.wants/indicator-datetime.service
/usr/lib/systemd/user/unity-panel-service-lockscreen.service.wants/indicator-keyboard.service
/usr/lib/systemd/user/unity-panel-service-lockscreen.service.wants/indicator-power.service
/usr/lib/systemd/user/unity-panel-service-lockscreen.service.wants/indicator-session.service
/usr/lib/systemd/user/unity-panel-service-lockscreen.service.wants/indicator-sound.service
/usr/lib/systemd/user/unity-panel-service.service
/usr/lib/systemd/user/unity-panel-service.service.wants/
/usr/lib/systemd/user/unity-panel-service.service.wants/indicator-application.service
/usr/lib/systemd/user/unity-panel-service.service.wants/indicator-bluetooth.service
/usr/lib/systemd/user/unity-panel-service.service.wants/indicator-datetime.service
/usr/lib/systemd/user/unity-panel-service.service.wants/indicator-keyboard.service
/usr/lib/systemd/user/unity-panel-service.service.wants/indicator-messages.service
/usr/lib/systemd/user/unity-panel-service.service.wants/indicator-power.service
/usr/lib/systemd/user/unity-panel-service.service.wants/indicator-printers.service
/usr/lib/systemd/user/unity-panel-service.service.wants/indicator-session.service
/usr/lib/systemd/user/unity-panel-service.service.wants/indicator-sound.service
/usr/lib/systemd/user/unity-screen-locked.target