Add workaround for null access test failure

src/vs/workbench/services/views/browser/viewDescriptorService.ts

@@ -223,7 +223,7 @@ export class ViewDescriptorService extends Disposable implements IViewDescriptor
 	) {
 		super();
 
-		storageKeysSyncRegistryService.registerStorageKey({ key: ViewDescriptorService.CACHED_VIEW_POSITIONS, version: 1 });
+		storageKeysSyncRegistryService?.registerStorageKey({ key: ViewDescriptorService.CACHED_VIEW_POSITIONS, version: 1 });
 		this.viewDescriptorCollections = new Map<ViewContainer, { viewDescriptorCollection: ViewDescriptorCollection, disposable: IDisposable; }>();
 		this.activeViewContextKeys = new Map<string, IContextKey<boolean>>();
 		this.movableViewContextKeys = new Map<string, IContextKey<boolean>>();