bug(MatDatePicker): change events emitted despite using emitEvents false

#### Reproduction

https://stackblitz.com/edit/components-issue-xay9ty?file=src%2Fapp%2Fexample-component.ts

1. Click the "emitEvent: false" button

#### Expected Behavior

`valueChanges` should not emit values when setting a value with `emitEvent: false`

This works correctly for "normal" input components, but not when attaching a date picker.

The reproduction includes a text input and a select for comparison.

#### Actual Behavior

Using `setValue` or `patchValue` with `emitEvent` set to `false` has the `valueChanges` observable emit changes.

#### Environment

- Angular: 10.0.3
- CDK/Material: 10.0.3
- Browser: Chrome
- Operating System: Windows

打开链接的 StackBlitz 复现，并检查 src/app/example-component.ts。点击 "emitEvent: false" 按钮，将 date-picker 的行为与文本输入框和 select 进行比较，并跟踪 valueChanges 的发出情况。当使用 emitEvent: false 调用 setValue 和 patchValue 时，date-picker 不产生任何 valueChanges 发出，即表示完成。

由索引模型根据 Issue 内容生成。