Merge branch '441981-add-assignment-for-showcase-project-templates-during-registration' into 'master' 

Add assignment for experiment: project_templates_during_registration

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/159582



Merged-by: Stan Hu <stanhu@gmail.com>
Approved-by: Aditya Tiwari <atiwari@gitlab.com>
Approved-by: Stan Hu <stanhu@gmail.com>
Co-authored-by: rliu-gl <rliu@gitlab.com>