Upgrade @metamask/preferences-controller to version 20.0.0

A new major version of `@metamask/preferences-controller`, 20.0.0, is now available. This issue has been assigned to you and your team because you code-own this package in the `core` repo. If this package is present in this project, please prioritize upgrading it soon to unblock new features and bugfixes.

Search the repository for the declaration and current use of @metamask/preferences-controller, then confirm whether this project includes the package. Update the dependency to 20.0.0 and run the relevant existing checks to verify that the extension still builds and tests pass.

Written by the indexing model from the issue text.