add ingress nginx webhook (#9033)

* add ingress nginx webhook

* fix ingress nginx template

roles/kubernetes-apps/ingress_controller/ingress_nginx/templates/role-admission-webhook.yml.j2

@@ -0,0 +1,17 @@
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  labels:
+    app.kubernetes.io/name: ingress-nginx
+    app.kubernetes.io/part-of: ingress-nginx
+  name: ingress-nginx-admission
+  namespace: {{ ingress_nginx_namespace }}
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - secrets
+  verbs:
+  - get
+  - create