bug(mat-dialog): mat-dialog-content always has a scroll bar when there is a element with ripple overflowing inside

#### Reproduction

Steps to reproduce:
put a mat-slide-toggle in a mat-dialog-content

https://stackblitz.com/edit/angular-pt8j22?file=src/app/dialog-content-example-dialog.html

**EDIT: same goes for checkboxes**

#### Expected Behavior
there should not be a scroll bar when having a mat-slide-toggle in a mat-dialog-content if the content does not exceed the max height allowed

#### Actual Behavior
mat-dialog-content always has a scroll bar when there is a mat-slide-toggle inside it

#### Environment

- Angular: 10
- CDK/Material: 10
- Browser(s): Chrome
- Operating System (e.g. Windows, macOS, Ubuntu): Windows

从链接的 StackBlitz 复现开始，具体查看 src/app/dialog-content-example-dialog.html，并运行包含 mat-slide-toggle 或复选框的对话框。比较有无溢出 ripple 元素时的 mat-dialog-content；当内容保持在允许的高度以内时，对话框没有滚动条即表示完成。

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