Project settings permission toggles cause accidental change in access level

Related to https://gitlab.com/gitlab-org/gitlab/-/issues/492317#note_2163216308 (internal link)

Steps to reproduce

1. Create a private project
2. Go to that project -> Settings -> General -> Visibility, project features, permissions
3. Toggle the Issues toggle off then back on
4. Save the page.
5. The access level will have changed from 20 to 10 by accident

Implementation guide

There is something funky going on with the logic in https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/assets/javascripts/pages/projects/shared/permissions/components/project_feature_setting.vue#L72. We may need to keep track of the initial value of the value prop and then change back to that if it gets toggled back on. This will take a bit of digging. Weighting a 3 because there are unknowns.