Fix: Fixed high contrast support in menu flyouts

[0x5bfa]

Summary

This PR contains abount two topic

• Fix backplate issue on a flyout
• Fix red coloring by adding "Brush" suffix

PR Checklist

• Were these changes approved in an issue or discussion with the project maintainers? In order to prevent extra work, feature requests and changes to the codebase must be approved before the pull request will be reviewed. This prevents extra work for the contributors and maintainers.
  Issue: Bug: Backplates will be displayed when hovering in High Contrast #13078
• Did you build the app and test your changes?
• Did you check for accessibility? You can use Accessibility Insights for this.
• Did you remove any strings from the en-us resource file?
  • Did you search the solution to see if the string is still being used?
• Did you implement any design changes to an existing feature?
  • Was this change approved?
• Are there any other steps that were used to validate these changes?
  1. Launch the app
  2. Right click a storage item
  3. See no backplates

Screenshots

Before	After

Before	After

[yaira2]

Thank you