Enable portmap CNI plugin with kube-router (#6204)

... to have working `hostPort` for containers.

See: https://www.kube-router.io/docs/user-guide/#hostport-support

roles/network_plugin/kube-router/templates/cni-conf.json.j2

@@ -16,6 +16,12 @@
 {% endif %}
             "type":"host-local"
          }
+      },
+      {
+         "type":"portmap",
+         "capabilities":{
+            "portMappings":true
+         }
       }
    ]
 }