Add code coverage for CheckBoxBaseAdapter

[Zheng-Li01]

Related #13442

Proposed changes

Add unit test file:CheckBoxBaseAdapterTests.cs for public/protected methods/properties of the CheckBoxBaseAdapter.cs

Microsoft Reviewers: Open in CodeFlow

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 51.68798%. Comparing base (8a682dd) to head (52e2ef8).
⚠️ Report is 12 commits behind head on main.

❗ There is a different number of reports uploaded between BASE (8a682dd) and HEAD (52e2ef8). Click for more details.

HEAD has 2 uploads less than BASE

Flag	BASE (8a682dd)	HEAD (52e2ef8)
Debug	3	2
test	1	0

Additional details and impacted files

@@                 Coverage Diff                  @@
##                main      #13752          +/-   ##
====================================================
- Coverage   76.89862%   51.68798%   -25.21064%     
====================================================
  Files           3262        2064        -1198     
  Lines         643611      288125      -355486     
  Branches       47631       42088        -5543     
====================================================
- Hits          494928      148926      -346002     
+ Misses        145013      136295        -8718     
+ Partials        3670        2904         -766     

Flag	Coverage Δ
Debug	51.68798% <ø> (-25.21064%)	⬇️
integration	18.98897% <ø> (-0.00196%)	⬇️
production	51.68798% <ø> (+0.11674%)	⬆️
test	?
unit	49.09675% <ø> (+0.11954%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[ricardobossan]

Thank you!