Example: Remove dispatching of 2 actions in AppComponent

[brandonroberts]

In the example app, we dispatching 2 actions when the logout nav item is clicked, one to close the sidenav and one to display the logout confirmation. This should be done with one action, with the layout reducer listening for the logout confirmation action.

https://github.com/ngrx/platform/blob/master/projects/example-app/src/app/core/containers/app.component.ts#L65

https://github.com/ngrx/platform/blob/master/projects/example-app/src/app/core/reducers/layout.reducer.ts#L18