image: T9269: skip GRUB updates on container and diskless systems

Kernel cmdline and serial console updates rewrite the GRUB configuration on
the persistence partition. A container has no GRUB at all, and on a system
where the persistence partition is not mounted disk.find_persistence()
returns an empty string, so the code reads '//boot/grub/grub.cfg' and dies
with FileNotFoundError.

Extend is_running_as_container() to also honor /run/.containerenv (Podman)
and the container= variable systemd sets for PID 1, and add if_not_container()
plus if_persistence() decorators guarding all grub_util entry points.

0 files changed, 0 insertions, 0 deletions