Add stricter types for bare-metal modules

* Review variables available in bare-metal kubernetes modules
for Container Linux and Fedora CoreOS
* Deprecate cluster_domain_suffix variable
* Remove deprecated container_linux_oem variable

bare-metal/container-linux/kubernetes/cl/install.yaml.tmpl

@@ -35,7 +35,6 @@ storage:
             -d ${install_disk} \
             -C ${os_channel} \
             -V ${os_version} \
-            -o "${container_linux_oem}" \
             ${baseurl_flag} \
             -i ignition.json
           udevadm settle