Dashboard: Force update after dashboard resize (#17808)

public/app/features/dashboard/dashgrid/DashboardGrid.tsx

@@ -163,6 +163,7 @@ export class DashboardGrid extends PureComponent<Props> {
     for (const panel of this.props.dashboard.panels) {
       panel.resizeDone();
     }
+    this.forceUpdate();
   };
 
   onViewModeChanged = () => {