[Unit]
Description=Unattended Upgrades Shutdown
After=network.target local-fs.target systemd-logind.service
RequiresMountsFor=/run /var/log /var/run /var/lib /boot
Documentation=man:unattended-upgrade(8)

[Service]
ExecStart=/usr/share/unattended-upgrades/unattended-upgrade-shutdown --wait-for-signal
KillMode=process
TimeoutStopSec=1800

[Install]
WantedBy=multi-user.target