Resolve issues associated with Calico deployment in policy-only mode. (#3392)

roles/network_plugin/calico/templates/calico-config.yml.j2

@@ -10,10 +10,11 @@ data:
   etcd_key: "/calico-secrets/key.pem"
 {% if calico_network_backend is defined and calico_network_backend == 'none' %}
   cluster_type: "kubespray"
-{%- else %}
+  calico_backend: "none"
+{% else %}
   cluster_type: "kubespray,bgp"
-{% endif %}
   calico_backend: "bird"
+{% endif %}
 {% if inventory_hostname in groups['k8s-cluster'] and peer_with_router|default(false) %}
   as: "{{ local_as|default(global_as_num) }}"
 {% endif -%}