By default today, the container is always started if its pod is also
started. This prevents to create custom with systemd where containers in
a pod could be started through their `[Install]` section.
We add a key `StartWithPod=`, enabled by default, that enables one to
disable that behavior.
This prevents the pod service from changing the state of the container
service.
Fixes#24401
Signed-off-by: Farya L. Maerten <me@ltow.me>
2597eeae70