fix(button-toggle): allow event bubbling for toggle button clicks (#11951)

src/lib/button-toggle/button-toggle.html

@@ -6,7 +6,7 @@
         [attr.name]="name || null"
         [attr.aria-label]="ariaLabel"
         [attr.aria-labelledby]="ariaLabelledby"
-        (click)="_onButtonClick($event)">
+        (click)="_onButtonClick()">
   <div class="mat-button-toggle-label-content">
     <ng-content></ng-content>
   </div>

src/lib/button-toggle/button-toggle.ts

@@ -436,9 +436,7 @@ export class MatButtonToggle extends _MatButtonToggleMixinBase implements OnInit
   }
 
   /** Checks the button toggle due to an interaction with the underlying native button. */
-  _onButtonClick(event: Event) {
-    event.stopPropagation();
-
+  _onButtonClick() {
     const newChecked = this._isSingleSelector ? true : !this._checked;
 
     if (newChecked !== this._checked) {