test(loading): add test to show setting dynamic content

references #6103

src/components/loading/test/basic/index.ts

@@ -83,11 +83,16 @@ class E2EPage {
       content: `
         <div class="custom-spinner-container">
           <div class="custom-spinner-box"></div>
-        </div>`,
+        </div>`
-      duration: 1000
     });
 
     loading.present();
+    setTimeout(() => {
+      loading.setContent("Loaded!");
+    }, 1000);
+    setTimeout(() => {
+      loading.dismiss();
+    }, 2000);
   }
 
   presentLoadingText() {

src/components/nav/view-controller.ts

@@ -79,9 +79,9 @@ export class ViewController {
   didUnload: EventEmitter<any>;
 
   /**
-   * @protected
+   * @internal
    */
-  protected data: any;
+  data: any;
 
   /**
    * @private