For #5356 Improved private browsing "common myths" link accessibility

[mcarare]

Added separate TextView for link text
Used UnderlineSpan to show text as link
Split string private_browsing_placeholder, one for each TextView
Set clickListener on TextView so it can be accessed via Talkback

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
• 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

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-io]

Codecov Report

Merging #5479 into master will increase coverage by <.01%.
The diff coverage is 0%.

@@             Coverage Diff             @@
##             master   #5479      +/-   ##
===========================================
+ Coverage     13.09%   13.1%   +<.01%     
  Complexity      289     289              
===========================================
  Files           252     252              
  Lines         10367   10365       -2     
  Branches       1504    1504              
===========================================
  Hits           1358    1358              
+ Misses         8916    8914       -2     
  Partials         93      93

Impacted Files	Coverage Δ	Complexity Δ
...iewholders/PrivateBrowsingDescriptionViewHolder.kt	0% <0%> (ø)	0 <0> (ø)	⬇️

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[sblatz]

Tested manually and looks good to me. Thanks for this patch 😄