Language Selection in GDM missing

I just installed a fresh RHEL 7.2 with a RPM and Group list which also I used for RHEL 7.1 before.
In my fresh RHEL 7.2 installation, the language selector is missing in the GDM greeter.
When I update an RHEL 7.1 (yum update) to the current RHEL 7.2 repo I still have the language selector in the GDM greeter.

How can I reconfigure or reinstall the language selector in GDM login screen?
I tried the localectl mentioned in the Desktop_Migration_and_Administration_Guide (section 10.4) - no luck.
i checked the /etc/gdm files. No differences between 7.1 and 7.2.

Thank you in advance
Stephan