Bug 1880087 - TestSetup helper: Test classes D-L

[sv-ohorvath]

Waiting for #5536 to land first.

Pull Request checklist

• Quality: This PR builds and passes detekt/ktlint checks (A pre-push hook is recommended)
• Tests: This PR includes thorough tests or an explanation of why it does not
• Changelog: This PR includes a changelog entry or does not need one
• Accessibility: The code in this PR follows accessibility best practices or does not include any user facing features

After merge

• Breaking Changes: If this is a breaking Android Components change, please push a draft PR on Reference Browser to address the breaking issues.

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3. Click on the build-apk-{fenix,focus,klar}-debug task you're interested in.
4. Click on View task in Taskcluster in the new DETAILS section.
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GitHub Automation

https://bugzilla.mozilla.org/show_bug.cgi?id=1880087

[mergify]

This pull request has conflicts when rebasing. Could you fix it @sv-ohorvath? 🙏

[sv-ohorvath]

#5536 landed, this is ready for review.

[AndiAJ]

👍🏽