feat(MatChipList): add better out-of-the-box support for FormControls

#### Reproduction

Use StackBlitz to reproduce your issue: https://stackblitz.com/edit/chips-autocomplete-required-failure?file=app/chips-autocomplete-example.ts

Steps to reproduce:
1. Fork the mat-chips autocomplete example from the Angular documentation
2. Move the form control to the mat-chip-list and add required attribute
3. Try using the auto complete 💥

NOTE: Followed suggestion in the following issue to add the required field, but that example doesn't include autocomplete. With this the autocomplete breaks. https://github.com/angular/components/issues/14195

#### Expected Behavior

The autocomplete should filter results based on text entered.

#### Actual Behavior

The autocomplete does not filter the results based on the text input from the user.

#### Environment

- Angular: 8.2.14
- CDK/Material: 8.2.3
- Browser(s): Chrome 81.0.4044.138
- Operating System (macOS): Mojave 10.14.6

Comienza con la reproducción de StackBlitz en app/chips-autocomplete-example.ts y compárala con el Angular Material chips autocomplete example y el Issue 14195. Reproduce el fallo moviendo el FormControl a mat-chip-list y añadiendo required; después, sigue la interacción entre MatChipList y autocomplete. El trabajo estará terminado cuando autocomplete filtre los resultados a partir del texto del usuario y el control required siga siendo compatible.

Escrito por el modelo de indexación a partir del texto del issue.