Product discovery for default group dashboard settings in CE (follow-up)
### Problem to solve
Currently, the "Group Overview content" preference is supposed to be EE-only. This means that EE and CE database laoyouts and (less important) templates will diverge more. This would increases future difficulties of making a [single codebase](https://gitlab.com/gitlab-org/gitlab-ee/issues/2952#note_41016454) for GitLab.
### Target audience
Sasha, Software Developer, https://design.gitlab.com/research/personas#persona-sasha
### Proposal
Enable "Group Overview content" preference for all CE users. Represent it as a dropdown labeled `"Group Overview content"` with 2 options: `"Details (default)"` and `"Activity"`. Minimum tier: `Core`.
### What does success look like, and how can we measure that?
Success metrics: increasing usage ping for choosing the `"Activity"` option for `"Group Overview content"` after releasing this feature.
Acceptance criteria: "Group Overview content" preference is available in CE for user roles including `Developer` and higher, starting from `Core` tier.
### Links / references
This proposal was [initially suggested](https://gitlab.com/gitlab-org/gitlab-ee/issues/7048#note_136152882) by @reprazent while discussing the [implementation](https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9332) of [Group Overview content for EE](https://gitlab.com/gitlab-org/gitlab-ee/issues/7048).
Also, this is related to the [product discovery](https://gitlab.com/gitlab-org/gitlab-ce/issues/52293) for the same feature in EE.
issue