message: fix(forms): expose ControlConfig in public API
  This commit exposes the ControlConfig as a public API, so that the symbol can be used in applications.
  PR Close
diff: @@ -175,6 +175,9 @@ export class CheckboxRequiredValidator extends RequiredValidator {
  // @public
  export const COMPOSITION_BUFFER_MODE: InjectionToken<boolean>;
  +// @public
  +export type ControlConfig<T> = [T | FormControlState<T>, (ValidatorFn | (ValidatorFn[]))?, (AsyncValidatorFn | AsyncValidatorFn[])?];
  +
  // @public
  export abstract class ControlContainer extends AbstractControlDirective {
  get formDirective(): Form | null;
  