Sorting a mat-table with expandable rows causes rows to not expand on first click

#### Bug, feature request, or proposal:

Bug

#### What is the expected behavior?

Sorting the mat-table should not affect the expansion of the rows. The behavior should act as in the example table:
https://stackblitz.com/angular/keapqmllkjp?file=app%2Ftable-expandable-rows-example.ts

#### What is the current behavior?

After clicking on a column with sort capabilities and sorting the table, the expandable rows do not open on first click. Clicking a second time will expand the row.

#### What are the steps to reproduce?

https://stackblitz.com/edit/angular-c8kwxe?file=app%2Ftable-expandable-rows-example.ts
1.) Click on a column-header to sort the table
2.) Click the rows to expand
3.) Once you've clicked on a row and it does not expand, clicking on it again will result in nothing. To get it to expand, you have to click another row and then re-click the row again.

#### Which versions of Angular, Material, OS, TypeScript, browsers are affected?

#### Is there anything else we should know?

Oddly, if you cycle through all of the sorted states and get the rows to expand through each state, the rows will then behave normally after doing another sort.

Reproduziere das Problem anhand der verknüpften StackBlitz-Beispiele, beginnend mit app/table-expandable-rows-example.ts und den Interaktionen zwischen mat-table-Sortierung und aufklappbaren Zeilen. Vergleiche das Verhalten vor und nach dem Sortieren; abgeschlossen ist die Aufgabe, wenn sich Zeilen nach jedem Sortierstatus beim ersten Klick aufklappen, entsprechend dem erwarteten Beispiel.

Vom Indexierungsmodell aus dem Issue-Text verfasst.