Mobile: Click event is fired when Nested MatMenu is hidden

#### What is the expected behavior?
In mobile, clicking anywhere on the parent navigation mat-menu should only execute the sub menu. Then click on the submenu, with a routerLink, to see another page.

#### What is the current behavior?
In mobile, if the sub-menu overlaps the parent mat-menu the routerLink in the sub-menu gets executed, even when the sub-menu is hidden.

#### What are the steps to reproduce?
In a mobile device go to: https://angular-aor8v8.stackblitz.io/
Source: https://stackblitz.com/edit/angular-aor8v8?file=app%2Fnested-menu-example.html
Example: http://recordit.co/JopTv4JWTU

#### Which versions of Angular, Material, OS, TypeScript, browsers are affected?
Angular 7.1.1
Material 7.1.1
Chrome

#### Is there anything else we should know?
I tried the lazy rendering with matMenuContent and it didn't seem to have any affect.
Also, tested on an iOS device and it works perfectly fine

首先使用链接的 StackBlitz 示例，尤其是 app/nested-menu-example.html，重现移动端行为，并将其与预期的父菜单和子菜单交互进行比较。跟踪子菜单隐藏时嵌套 mat-menu 的点击和 routerLink 行为；完成标准是点击父菜单不会激活隐藏子菜单的链接，而点击可见的子菜单链接仍会进行导航。

由索引模型根据 Issue 内容生成。