Depending on the podman version, "json-file" is set to noop and makes
podman crash (true for at least podman 1.4.1), while older versions
re-add this json-file as an alias to k8s-file (true since 1.4.3).
Ensuiring we're using k8s-file will prevent issues depending on the
podman version.
Relates to https://bugzilla.redhat.com/show_bug.cgi?id=1754416
Closes-Bug: #1844856
Change-Id: I70eba8af06741ed81173689a03c4867421917cd6
(cherry picked from commit 0976e4eeb3)