src/vs/workbench/browser/layout.ts/Layout/getDefaultLayoutViews
class Layout:	private getDefaultLayoutViews(environmentService: IBrowserWorkbenchEnvironmentService, storageService: IStorageService): string[] | undefined {
		const defaultLayout = environmentService.options?.defaultLayout;
		if (!defaultLayout) {
			return undefined;
		}

		if (!defaultLayout.force && !storageService.isNew(StorageScope.WORKSPACE)) {
			return undefined;
		}

		const { views } = defaultLayout;
		if (views?.length) {
			return views.map(view => view.id);
		}

		return undefined;
	}