Prevent attr_encrypted models from being overriden
What does this MR do?
CE port of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/8189
What are the relevant issue numbers?
https://gitlab.com/gitlab-org/gitlab-ee/issues/8234
Does this MR meet the acceptance criteria?
[ ] Changelog entry added, if necessaryDocumentation created/updated-
Tests added for this feature/bug -
Conforms to the code review guidelines -
Conforms to the merge request performance guidelines -
Conforms to the style guides Conforms to the database guides- ~~Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.~~