Drag Drop: mat-grid-tile does not retain height when being dragged

#### What is the expected behavior?
When dragging an item in a list, element rendered next to the user's cursor should look exactly like the element that is being dragged.

#### What is the current behavior?
Height changes and becomes bigger when item is being dragged

#### What are the steps to reproduce?
I use Mat-Grid-List example available in the docs at https://stackblitz.com/angular/oegmxkolgyr?file=app%2Fgrid-list-overview-example.html

Just display it on one line because of "Drag Drop Sortable, mixed orientation support (#13372 )" bug and add drag/drop like this:

```

1
2
3
4

```


When rowHeight is set to a ratio, height of item being drag changes.

Any solution to keep height at correct ratio?

Commencez par reproduire le problème dans le StackBlitz lié en utilisant le balisage mat-grid-list et un rowHeight basé sur un ratio. Examinez l’interaction entre mat-grid-tile et drag/drop pendant l’aperçu du glisser-déposer. Le travail est terminé lorsque la tuile déplacée conserve le même ratio hauteur-largeur que la tuile d’origine.

Rédigé par le modèle d'indexation à partir du texte de l'issue.