bug(table): ngOnDestroy clears view before route animations finish

#### Reproduction

https://angular-components-8057.stackblitz.io (updated to 9.2.4)

Steps to reproduce:
1. Navigate to "Page" and the table view is destroyed immediately.

#### Expected Behavior

Table should remain in DOM until animations finish.

#### Actual Behavior

Table is removed from DOM as soon as routing begins.

#### Environment

- Angular: 9.1.9
- CDK/Material: 9.2.4
- Browser(s): Google Chrome
- Operating System (e.g. Windows, macOS, Ubuntu): macOS

Start with the linked StackBlitz reproduction and trace what happens when routing begins, focusing on why the table view is destroyed before the route animation completes. Done means the table remains in the DOM until the animation finishes, while the reproduction no longer shows immediate removal.

Written by the indexing model from the issue text.