kubelet: Configure cri-o container registries

The _containers-image_ role configures _containers-registries.conf(5)_ and
_containers-cert.d(5)_, which are used by CRI-O (and `podman`).
Specifically, we'll use these to redirect requests for images on Docker
Hub (docker.io) to the internal caching proxy.

roles/containers-image/defaults/main.yml

@@ -0,0 +1,2 @@
+container_registries: []
+container_registry_certs: {}