Datepicker: When selecting a month in a year/month mode, the day selection flashes on click

#### Reproduction

https://stackblitz.com/angular/kgvngvkblme?file=src%2Fapp%2Fdatepicker-views-selection-example.ts

Steps to reproduce:
1. Click on the calendar icon
2. Select a year
3. Select a month

This is actually the example from https://material.angular.io/components/datepicker/overview, although I found it more noticeable in my app

#### Expected Behavior

The datepicker calendar should close immediately.

#### Actual Behavior

When clicked on the month, the calendar briefly switches into monthly view (therefore displaying all the weeks and days), before closing.

#### Environment

- Angular: 10.2.0
- CDK/Material: 10.2.5
- Browser(s): Chrome
- Operating System (e.g. Windows, macOS, Ubuntu): macOS

StackBlitz の再現から始め、特に src/app/datepicker-views-selection-example.ts を確認し、Angular datepicker で年、続いて月を選択する動作を再現します。月を選択した後の遷移を追跡し、日ビューを一瞬表示することなくカレンダーが直ちに閉じることを確認します。

索引モデルが issue の本文から書いたものです。