Make sure #extract! will keep `permitted` value

Hello,

This is just a little pull request that makes `#extract!` keep the `@permitted` value when calling on an `ActionController::Parameters` object. Previously, it was relying on its superclass' (i.e.`HashWithIndifferentAccess` which is inheriting from `Hash`).

Let me know if you want me to do any backport to the strong_parameters repository.

Fixes #13830.

Have a nice day.