[deployment][ocis-keycloak] New group can be created from ocis

Using example deployemnt of `ocis_keycloak` from https://github.com/owncloud/ocis/tree/master/deployments/examples/ocis_keycloak, new group can be created from the ocis webUI.
- a group created from oCIS webUI not synced to keycloak

### Expectation
new group should not be created from oCIS webUI but only from keycloak dashboard

### Related issue
- issue for user creation is reported previously https://github.com/owncloud/ocis/issues/7098.

CC @rhafer @mmattel