BlockScrollStrategy affects supportsScrollBehavior method in IE11

[wonderlaw1]

Reproduction

Use StackBlitz to reproduce your issue: https://stackblitz.com/edit/angular-cdk-overlay-issue-apycr4

Steps to reproduce:

1. Open example in IE11
2. Click "Open Dialog" button
3. Close Dialog
4. Click "Check supportsScrollBehavior" button
5. Open console
6. "ERROR!!! IE11 doesn't support scroll-behavior" message presented into the console

Expected Behavior

BlockScrollStrategy.disable shouldn't add "scroll-behavior" style property to html element by design.

Actual Behavior

BlockScrollStrategy.disable was called by MatDialog and it mutates style object of html element by adding scrollBehavior property into it. Due to specification this property shouldn't be. And it affects also supportsScrollBehavior method, because after BlockScrollStrategy.disable call IE11 "supports" scroll-behavior, but it doesn't.

Environment

• Angular: 8.0+
• CDK/Material: 8.0+
• Browser(s): IE11
• Operating System (e.g. Windows, macOS, Ubuntu): Windows 10