FNX-14467 ⁃ Disable flaky tests: settingsAddonsItemsTest, verifyAboutFirefoxPreview

[rpappalax]

See: #13218 #13219

Pull Request checklist

• Tests: This PR includes thorough tests or an explanation of why it does not
• Screenshots: This PR includes screenshots or GIFs of the changes made or an explanation of why it does not
• Accessibility: The code in this PR follows accessibility best practices or does not include any user facing features. In addition, it includes a screenshot of a successful accessibility scan to ensure no new defects are added to the product.

After merge

• Milestone: Make sure issues finished by this pull request are added to the milestone of the version currently in development.

To download an APK when reviewing a PR:

1. click on Show All Checks,
2. click Details next to "Taskcluster (pull_request)" after it appears and then finishes with a green checkmark,
3. click on the "Fenix - assemble" task, then click "Run Artifacts".
4. the APK links should be on the left side of the screen, named for each CPU architecture

[codecov-commenter]

Codecov Report

Merging #13286 into master will increase coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master   #13286   +/-   ##
=========================================
  Coverage     28.34%   28.34%           
  Complexity     1034     1034           
=========================================
  Files           420      420           
  Lines         16877    16876    -1     
  Branches       2196     2196           
=========================================
  Hits           4784     4784           
+ Misses        11748    11747    -1     
  Partials        345      345           

Impacted Files	Coverage Δ	Complexity Δ
...ug/java/org/mozilla/fenix/DebugFenixApplication.kt	0.00% <0.00%> (ø)	0.00% <0.00%> (ø%)

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