[kubeadm] use v1beta3 configuration version

* extra admission controls now don't have a version in their file names
  eventratelimit.v1beta2.yaml.j2 -> eventratelimit.yaml.j2
* cri_socket variable includes the unix:// prefix to be conformat with
  upstream

roles/kubernetes/node/templates/kubelet.env.v1beta1.j2

@@ -13,7 +13,7 @@ KUBELET_HOSTNAME="--hostname-override={{ kube_override_hostname }}"
 --kubeconfig={{ kube_config_dir }}/kubelet.conf \
 {# end kubeadm specific settings #}
 --container-runtime=remote \
---container-runtime-endpoint=unix://{{ cri_socket }} \
+--container-runtime-endpoint={{ cri_socket }} \
 --runtime-cgroups={{ kubelet_runtime_cgroups }} \
 {% endset %}