fix(snackbar): wrap simple snackbar text in span

We have begun transforming our html templates in our internal syncs to include our license header
which results in a new line above template. In the simple snack bar this adds a single space when
looking at the elements textContent. By wrapping the content in a span we ensure that the
whitespace is consistent regardless of the presence of the license header comment in the template
file.

Author: josephperrott

src/demo-app/demo-app/demo-app.ts

@@ -8,6 +8,7 @@
 
 import {OverlayContainer} from '@angular/cdk/overlay';
 import {Component, ElementRef, ViewEncapsulation} from '@angular/core';
+import {Location} from '@angular/common';
 
 
 /**
@@ -97,7 +98,10 @@ export class DemoApp {
 
   constructor(
     private _element: ElementRef,
-    private _overlayContainer: OverlayContainer) {}
+    private _overlayContainer: OverlayContainer,
+    location: Location) {
+      location.subscribe(console.log);
+    }
 
   toggleFullscreen() {
     const elem = this._element.nativeElement.querySelector('.demo-content');

src/lib/snack-bar/simple-snack-bar.html

@@ -1,5 +1,4 @@
-{{data.message}}
-
+<span>{{data.message}}</span>
 <div class="mat-simple-snackbar-action"  *ngIf="hasAction">
   <button mat-button (click)="action()">{{data.action}}</button>
 </div>