Use existing variable for tiller service account name (#6829)

* Use existing variable for tiller service account name

* keep crb as tiller

roles/kubernetes-apps/helm/templates/tiller-clusterrolebinding.yml.j2

@@ -6,7 +6,7 @@ metadata:
   namespace: {{ tiller_namespace }}
 subjects:
   - kind: ServiceAccount
-    name: tiller
+    name: {{ tiller_service_account }}
     namespace: {{ tiller_namespace }}
 roleRef:
   kind: ClusterRole
@@ -20,7 +20,7 @@ metadata:
   name: psp:tiller
 subjects:
   - kind: ServiceAccount
-    name: tiller
+    name: {{ tiller_service_account }}
     namespace: {{ tiller_namespace }}
 roleRef:
   apiGroup: rbac.authorization.k8s.io

roles/kubernetes-apps/helm/templates/tiller-sa.yml.j2

@@ -2,5 +2,5 @@
 apiVersion: v1
 kind: ServiceAccount
 metadata:
-  name: tiller
+  name: {{ tiller_service_account }}
   namespace: {{ tiller_namespace }}