fix(checkbox): fix checkbox styles to be identic between projects

[didimmova]

Related to this issue

Additional information (check all that apply):

• Bug fix
• New functionality
• Documentation
• Demos
• CI/CD

Checklist:

• All relevant tags have been applied to this PR
• This PR includes unit tests covering all the new code (test guidelines)
• This PR includes API docs for newly added methods/properties (api docs guidelines)
• This PR includes feature/README.MD updates for the feature docs
• This PR includes general feature table updates in the root README.MD
• This PR includes CHANGELOG.MD updates for newly added functionality
• This PR contains breaking changes
• This PR includes ng update migrations for the breaking changes (migrations guidelines)
• This PR includes behavioral changes and the feature specification has been updated with them

[SisIvanova]

@didimmova Double check:

• Indigo theme invalid indeterminate focused state (both with and without Sass theme modifications)

• Bootstrap theme invalid focused hover state and invalid checked focused hover state (when modifying the Sass theme, there is a difference in the checkbox border)

Screen.Recording.2025-10-29.at.9.59.57.AM.mov