fix(Toolbar): Move the cancelation before changing isExporting & showProgress.

Author: gedinakova

projects/igniteui-angular/src/lib/grids/toolbar/grid-toolbar-exporter.component.ts

@@ -126,13 +126,14 @@ export class IgxGridToolbarExporterComponent extends BaseToolbarDirective {
 
         this.exportStarted.emit(args);
         this.grid.toolbarExporting.emit(args);
-        this.isExporting = true;
-        this.toolbar.showProgress = true;
 
         if (args.cancel) {
             return;
         }
 
+        this.isExporting = true;
+        this.toolbar.showProgress = true;
+
         exporter.exportEnded.pipe(first()).subscribe(() => {
             this.exportEnded.emit();
             this.isExporting = false;