add namespace.yaml into kustomization resource

base/kustomization.yaml

@@ -1,4 +1,5 @@
 resources:
+  - namespace.yaml
   - backend/backend-deployment.yaml
   - backend/be-networkpolicy.yaml
   - frontend/frontend-deployment.yaml
@@ -8,5 +9,4 @@ resources:
   - networkpolicy-default.yaml
   - configmap.yaml
   - secret.yaml
-  - rbac.yaml
-  - namespace.yaml
+  - rbac.yaml