window - flashFrame works on Linux too (microsoft#255996)

Author: bpasero

src/vs/platform/windows/electron-main/windowImpl.ts

@@ -369,7 +369,7 @@ export abstract class BaseWindow extends Disposable implements IBaseWindow {
 		disposables.add(DockBadgeManager.INSTANCE.acquireBadge(this));
 
 		// Flash/Bounce
-		if (isWindows) {
+		if (isWindows || isLinux) {
 			this.win?.flashFrame(true);
 			disposables.add(toDisposable(() => this.win?.flashFrame(false)));
 		} else if (isMacintosh) {