Log Message:
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Enable systemd to create /var/lib/lxc at runtime with StateDirectory
This change adds the StateDirectory= directive in the systemd
unit file to ensure that the /var/lib/lxc directory is
automatically created and managed by systemd during service startup.
The StateDirectory= option instructs systemd to create a persistent
state directory under /var/lib/. This is particularly useful in
scenarios where the directory may be missing at first boot — such as
on OSTree-based Linux distributions, which typically ship with
empty /var directory as part of their immutable root filesystem.
By adding StateDirectory=lxc, systemd will handle the creation of
/var/lib/lxc on first boot, ensuring that the service can start
reliably even when the directory is not present initially.