Refactor `spec/frontend/integrations/edit/components/active_checkbox_spec.js` to not mock Vuex getter
What does this MR do?
Per discussion in !34742 (comment 380594022), this MR updates this spec so that we mock the Vuex state instead of the getter, giving us test coverage of the getter for free.
Related to #229519 (closed)
Edited by Tom Quirk