fix(label): include the ion-text-wrap class styles for larger font (#18374)

- updates all e2e tests to use the CSS classes instead of attributes

core/src/components/buttons/test/icon/index.html

@@ -27,7 +27,7 @@
         </ion-buttons>
       </ion-toolbar>
     </ion-header>
-    <ion-content padding no-bounce text-center>
+    <ion-content class="ion-padding ion-text-center" no-bounce>
       Content
     </ion-content>