helm: fix resource not respect namespace (#9678)

**What this PR does / why we need it**:

this PR make all resources have some behavior when running `helm
template loki grafana/loki --name istio-system`

istio use it here:
https://github.com/istio/istio/blob/master/manifests/addons/gen.sh#L89

**Which issue(s) this PR fixes**:
Fixes #<issue number>

**Special notes for your reviewer**:

**Checklist**
- [x] Reviewed the
[`CONTRIBUTING.md`](https://github.com/grafana/loki/blob/main/CONTRIBUTING.md)
guide (**required**)
- [ ] Documentation added
- [ ] Tests updated
- [ ] `CHANGELOG.md` updated
- [ ] Changes that require user attention or interaction to upgrade are
documented in `docs/sources/upgrading/_index.md`
- [ ] For Helm chart changes bump the Helm chart version in
`production/helm/loki/Chart.yaml` and update
`production/helm/loki/CHANGELOG.md` and
`production/helm/loki/README.md`. [Example
PR](d10549e3ec)

Signed-off-by: hejianpeng <hejianpeng2@huawei.com>

production/helm/loki/templates/config.yaml

@@ -7,6 +7,7 @@ kind: ConfigMap
 {{- end }}
 metadata:
   name: {{ tpl .Values.loki.externalConfigSecretName . }}
+  namespace: {{ $.Release.Namespace }}
   labels:
     {{- include "loki.labels" . | nindent 4 }}
 {{- if eq .Values.loki.configStorageType "Secret" }}