For #11542: Update tabs positions in tab tray reported by screen readers

[mcarare]

Fixes #11542

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.

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[codecov-commenter]

Codecov Report

Merging #11636 into master will decrease coverage by 0.03%.
The diff coverage is 0.00%.

@@             Coverage Diff              @@
##             master   #11636      +/-   ##
============================================
- Coverage     21.55%   21.51%   -0.04%     
  Complexity      700      700              
============================================
  Files           373      373              
  Lines         15066    15090      +24     
  Branches       2036     2038       +2     
============================================
  Hits           3247     3247              
- Misses        11537    11561      +24     
  Partials        282      282              

Impacted Files	Coverage Δ	Complexity Δ
...java/org/mozilla/fenix/tabtray/FenixTabsAdapter.kt	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...main/java/org/mozilla/fenix/tabtray/TabTrayView.kt	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...ava/org/mozilla/fenix/tabtray/TabTrayViewHolder.kt	32.43% <0.00%> (-5.67%)	7.00 <0.00> (ø)
app/src/main/java/org/mozilla/fenix/Config.kt	33.33% <0.00%> (ø)	2.00% <0.00%> (ø%)
.../java/org/mozilla/fenix/utils/RunWhenReadyQueue.kt	0.00% <0.00%> (ø)	0.00% <0.00%> (ø%)

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