DeprecationWarning occurs when indentfirst=None is specified in coredns-config.yml.j2 (#8224)

roles/kubernetes-apps/ansible/templates/coredns-config.yml.j2

@@ -65,5 +65,5 @@ data:
     }
 {% if dns_etchosts | default(None) %}
   hosts: |
-    {{ dns_etchosts | indent(width=4, indentfirst=None) }}
+    {{ dns_etchosts | indent(width=4, first=False) }}
 {% endif %}

roles/kubernetes-apps/ansible/templates/nodelocaldns-config.yml.j2

@@ -163,5 +163,5 @@ data:
 {% endif %}
 {% if dns_etchosts | default(None) %}
   hosts: |
-    {{ dns_etchosts | indent(width=4, indentfirst=None) }}
+    {{ dns_etchosts | indent(width=4, first=False) }}
 {% endif %}

roles/kubernetes-apps/ingress_controller/cert_manager/templates/cert-manager.yml.j2

@@ -879,7 +879,7 @@ spec:
 apiVersion: v1
 data:
   internal-ca.pem: |
-    {{ cert_manager_trusted_internal_ca | indent(width=4, indentfirst=False) }}
+    {{ cert_manager_trusted_internal_ca | indent(width=4, first=False) }}
 kind: ConfigMap
 metadata:
   name: ca-internal-truststore