report telemetry on update check on product update (#226146)

src/vs/workbench/contrib/extensions/browser/extensionsWorkbenchService.ts

@@ -1072,6 +1072,10 @@ export class ExtensionsWorkbenchService extends Disposable implements IExtension
 		this._register(Event.debounce(this.onChange, () => undefined, 100)(() => this.hasOutdatedExtensionsContextKey.set(this.outdated.length > 0)));
 		this._register(this.updateService.onStateChange(e => {
 			if ((e.type === StateType.CheckingForUpdates && e.explicit) || e.type === StateType.AvailableForDownload || e.type === StateType.Downloaded) {
+				this.telemetryService.publicLog2<{}, {
+					owner: 'sandy081';
+					comment: 'Report when update check is triggered on product update';
+				}>('extensions:updatecheckonproductupdate');
 				this.eventuallyCheckForUpdates(true);
 			}
 		}));