Geo: HTTP push to secondary specs

What does this MR do?

This MR adds QA specs for testing git push to secondary for HTTP. SSH tests will come later as further investigation is ongoing around why SSH keys are not sync'd to the Geo secondary.

Based off https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/7531

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ee/issues/7516

Does this MR meet the acceptance criteria?

• [ ] Changelog entry added, if necessary
• [ ] Documentation 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
• EE specific content should be in the top level /ee folder
• [ ] For a paid feature, have we considered GitLab.com plans, how it works for groups, and is there a design for promoting it to users who aren't on the correct plan?