add namespace in kustomization for resource patching

ptp-chat/kustomization.yaml

@@ -1,6 +1,8 @@
 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 
+namespace: ptp-chat
+
 resources:
   - ptp-chat-backend.yaml
   - ptp-chat-frontend.yaml
@@ -9,7 +11,6 @@ resources:
   - ptp-chat-istio.yaml
   - ptp-chat-sealed-secret.yaml
   - ptp-chat-pull-sealed-secret.yaml
-  - config-map-config.yaml
 
 configMapGenerator:
   - name: ptp-chat-frontend-env