For #11465 - Fix default engine for widget voice search

[codrut-topliceanu]

For #11465

Pull Request checklist

• Tests: This PR does not include any tests as it is only a minor change.
• Screenshots: This PR includes a GIF.
• Accessibility: The code in this PR follows accessibility best practices.

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• 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 #14015 into master will decrease coverage by 0.00%.
The diff coverage is 0.00%.

@@             Coverage Diff              @@
##             master   #14015      +/-   ##
============================================
- Coverage     29.67%   29.66%   -0.01%     
- Complexity     1133     1134       +1     
============================================
  Files           434      434              
  Lines         17483    17486       +3     
  Branches       2259     2260       +1     
============================================
  Hits           5188     5188              
- Misses        11916    11919       +3     
  Partials        379      379              

Impacted Files	Coverage Δ	Complexity Δ
...enix/settings/search/SearchEngineListPreference.kt	0.00% <0.00%> (ø)	0.00 <0.00> (ø)

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[codrut-topliceanu]

The issue seems to be located in SearchEngineListPreference.onCheckedChanged().
When a search engine is deleted onCheckedChanged() should be called, and then when...true -> onSearchEngineSelected(engine), however that never happens as wrapper is always null at that point.

[Mugurell]

Thanks for looking into this!