fix(accordion): emit panelCollapsing event once

Author: MonikaKirkova

projects/igniteui-angular/src/lib/accordion/accordion.component.spec.ts

@@ -209,6 +209,7 @@ describe('Rendering Tests', () => {
                 argsIng = { event: expArgs.event, cancel: expArgs.cancel, owner: accordion, panel: expArgs.owner };
             });
             accordion.panels[0].collapse();
+            accordion.panels[0].collapse();
             tick();
             fix.detectChanges();
 

projects/igniteui-angular/src/lib/accordion/accordion.component.ts

@@ -364,7 +364,9 @@ export class IgxAccordionComponent implements AfterContentInit, AfterViewInit, O
             });
             panel.contentCollapsing.pipe(takeUntil(this._unsubChildren$)).subscribe((args: IExpansionPanelCancelableEventArgs) => {
                 const evArgs: IAccordionCancelableEventArgs = { ...args, owner: this, panel: args.owner };
-                this.panelCollapsing.emit(evArgs);
+                if (!args.owner.closeAnimationPlayer?._started) {
+                    this.panelCollapsing.emit(evArgs);
+                }
                 if (evArgs.cancel) {
                     args.cancel = true;
                 }