Fix leak in UpDownBaseTests

[Youssef1313]

Fixes #13596

Proposed changes

• Call OnHandleDestroyed to unsubscribe from UserPreferenceChanged event and fix memory leak in tests.

Customer Impact

• None. Test only change.

Regression?

• No

Risk

• None. Test only change.

Screenshots

Before

After

Test methodology

Accessibility testing

Test environment(s)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.60399%. Comparing base (34128e7) to head (802819b).
Report is 49 commits behind head on main.

Additional details and impacted files

@@                 Coverage Diff                 @@
##                main      #13597         +/-   ##
===================================================
- Coverage   76.61783%   76.60399%   -0.01385%     
===================================================
  Files           3236        3253         +17     
  Lines         639376      641011       +1635     
  Branches       47313       47442        +129     
===================================================
+ Hits          489876      491040       +1164     
- Misses        145973      146313        +340     
- Partials        3527        3658        +131     

Flag	Coverage Δ
Debug	76.60399% <100.00000%> (-0.01385%)	⬇️
integration	18.98652% <ø> (+0.44123%)	⬆️
production	51.05822% <ø> (+0.03112%)	⬆️
test	97.41186% <100.00000%> (-0.00097%)	⬇️
unit	48.43821% <ø> (+0.02139%)	⬆️

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[LeafShi1]

LGTM with a little suggestion.

[Youssef1313]

@LeafShi1 Is this good to merge?