DEV: Fix `BAD CSRF` errors for admin POST requests when on Ember CLI (PR #12908)

I think this was a find-and-replace error :grinning_face_with_smiling_eyes:

GitHub

The title of this pull request changed from “DEV: Fix errors for admin POST requests when on Ember CLI” to "DEV: Fix BAD CSRF errors for admin POST requests when on Ember CLI