Fix all pending remote dev rubocop errors

What does this MR do and why?

Fix all pending remote dev rubocop errors after latest upgrade of gitlab-styles gem.

See related info:

• Engineering Week In Review entry (internal doc): https://docs.google.com/document/d/1JBdCl3MAOSdlgq3kzzRmtzTsFWsTIQ9iQg0RHhMht6E/edit#bookmark=id.8h10vff3aalg
• Testing Best Practices docs in relation to RSpec/NamedSubject: https://docs.gitlab.com/ee/development/testing_guide/best_practices.html#subject-and-let-variables

How to set up and validate locally

Run scripts/remote_development/run-smoke-test-suite.sh which will run rubocop with TODOs ignored, and all relevant tests

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.