ORIGINAL TITLE: [SERVER] Investigate changes in SERVER-70121: Ubuntu 18 packaging tests shows error with systemctl

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We need to ensure that our documentation reflects the following changes in this ticket:

• fork and pidFilePath are removed from mongod.conf
• PIDFile and type=forking are removed from mongod.service
• Adding fork to mongod.conf is an incompatible change under systemd, since it will disrupt systemd's ability to track the service state. Unfortunately, we don't have a good programmatic way of checking this.
• Requesting the service PID and state should be done via systemctl instead of PID files

  Description of Linked Ticket

  https://github.com/10gen/mongo/pull/7730#discussion_r984027371

[2022/09/29 19:51:53.645] /var/lib/dpkg/info/mongodb-enterprise-unstable-server.postinst: 44: /var/lib/dpkg/info/mongodb-enterprise-unstable-server.postinst: systemctl: not found

Probs just needs the systemd dependency

This is probably happening for more than just this test and we should make sure it is fixed everywhere