This fixes an issue where `TestBed.overrideComponent(MyComp, {})` would remove some properties including `providers` from the component. This was due to the override not properly dealing with getter fields on subclasses.
BREAKING CHANGE: - deprecations: * `withProviders`, use `TestBed.withModule` instead * `addProviders`, use `TestBed.configureTestingModule` instead * `TestComponentBuilder`, use `TestBed.configureTestModule` / `TestBed.override...` / `TestBed.createComponent` instead. Closes #10354