changelog: adds note for #13691

CHANGELOG.md

@@ -28,6 +28,7 @@
 * **Variables**: Fix text box template variable doesn't work properly without a default value [#13666](https://github.com/grafana/grafana/issues/13666)
 * **Dashboard**: Fix kiosk=1 url parameter should put dashboard in kiosk mode [#13764](https://github.com/grafana/grafana/pull/13764)
 * **LDAP**: Fix super admins can also be admins of orgs [#13710](https://github.com/grafana/grafana/issues/13710), thx [@adrien-f](https://github.com/adrien-f)
+* **Stackdriver**: stackdriver user-metrics duplicated response when multiple resource types [#13691](https://github.com/grafana/grafana/issues/13691)
 
 ### Minor