Use apps/v1 API group whenever possible (#8055)

The use of extensions/v1beta1, apps/v1beta1 and apps/v1beta2 API
groups should be discouraged.

Closes: #8049

docs/getting-started-guides/ubuntu/rancher.md

@@ -59,7 +59,7 @@ rules:
   verbs:
   - '*'
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   creationTimestamp: null
@@ -71,6 +71,7 @@ spec:
   selector:
     matchLabels:
       app: rancher
+      ima: pod
   strategy: {}
   template:
     metadata:
@@ -220,7 +221,7 @@ rules:
   verbs:
   - '*'
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   creationTimestamp: null