refactor(Metadata): Make `@Directive.providers` a `List<Object>`.
refactor(Metadata): Make `@Directive.providers` a `List<Object>`.

This will play nicer with strict inference rules around raw types. It was already as this type on the field, we just forgot to also use that type argument for the providers.

PiperOrigin-RevId: 238095872

matanlurey/angular,angulardart/angular,angulardart/angular,matanlurey/angular,angulardart/angular,matanlurey/angular