How to reconfigure the machine-id?

Issue

• A system needs to be reconfigured with a different machine-id, for example because of a hitting issue tracked by SECDATA-335

• I cloned a system and want to have it use a different machine-id than original system

• System cannot boot: Missing /etc/machine-id and /etc is mounted read-only

  # journalctl -p err
  systemd[1]: System cannot boot: Missing /etc/machine-id and /etc is mounted read-only.
  systemd[1]: Booting up is supported only when:
  systemd[1]: 1) /etc/machine-id exists and is populated.
  systemd[1]: 2) /etc/machine-id exists and is empty.
  systemd[1]: 3) /etc/machine-id is missing and /etc is writable.