buildah login and podman login with root do not share same
authfile, buildah uses /run/containers/0/auth.json while
podman uses /run/user/0/containers/auth.json resulted from
To ensure both podman and buildah can access the configured
registry, run login command with both.
It's mainly needed as container images are being pushed
with tripleoclient using sudo buildah push and buildah creds
are not setup.