Bug 1876751 - Remove redundant preferences from SettingsFragment

[t-p-white]

ℹ️ See BZ for full details.

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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GitHub Automation

https://bugzilla.mozilla.org/show_bug.cgi?id=1876751