Add E2E test of approval rules

What does this MR do?

Adds an E2E test of approval rules.

CE backport MR: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/32439

Closes gitlab-org/quality/testcases#115 (closed)

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content