The carousel can not show properly while in a modal

[ngstyle]

Reproduction link

https://stackblitz.com/edit/ng-zorro-antd-start-ss5b1a?file=src%2Fapp%2Fnz.modal.custom.component.ts

Steps to reproduce

1. Add a carousel in a modal
2. The carousel does not display according to the set width and height

What is expected?

The carousel width and height showed as set.

What is actually happening?

The carousel does not display according to the set width and height while in a modal.

Environment	Info
ng-zorro-antd	8.5.2
Browser	Chrome 80.0.3987.149

[wzhudev]

(Do) Please search issues before opening a new one.

https://github.com/NG-ZORRO/ng-zorro-antd/issues?q=is%3Aissue+modal+carousel+is%3Aclosed

Actually it's a known issue and we're working on a solution called unstable container.

[ngstyle]

(Do) Please search issues before opening a new one.

https://github.com/NG-ZORRO/ng-zorro-antd/issues?q=is%3Aissue+modal+carousel+is%3Aclosed

Actually it's a known issue and we're working on a solution called unstable container.

Sorry for the duplicate issue.

[hsuanxyz]

fixed via #4702