Add "Update" Priv for ServiceAccounts to pgo-cluster-role

Adds the update priv for ServiceAccounts to the 'pgo-cluster-role'
role as needed to reconcile service accounts.

Author: andrewlecuyer

installers/ansible/roles/pgo-operator/templates/cluster-rbac.yaml.j2

@@ -22,6 +22,7 @@ rules:
     verbs:
     - get
     - create
+    - update
     - delete
   - apiGroups:
       - rbac.authorization.k8s.io