change dns upstream condition for coredns (#8263)

upstream_dns_servers should change corefile config even resolvconf_mode=docker_dns

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

@@ -41,7 +41,7 @@ data:
 {% endif %}
         }
         prometheus :9153
-{% if resolvconf_mode == 'host_resolvconf' and upstream_dns_servers is defined and upstream_dns_servers|length > 0 %}
+{% if upstream_dns_servers is defined and upstream_dns_servers|length > 0 %}
         forward . {{ upstream_dns_servers|join(' ') }} {
           prefer_udp
         }