Fix _initialize (#9206)

* Fix _initialize

* Update ha-demo.ts

cast/src/receiver/layout/hc-demo.ts

@@ -33,10 +33,10 @@ class HcDemo extends HassElement {
 
   protected firstUpdated(changedProps) {
     super.firstUpdated(changedProps);
-    this._initialize();
+    this._initializeHass();
   }
 
-  private async _initialize() {
+  private async _initializeHass() {
     const initial: Partial<MockHomeAssistant> = {
       // Override updateHass so that the correct hass lifecycle methods are called
       updateHass: (hassUpdate: Partial<HomeAssistant>) =>

demo/src/ha-demo.ts

@@ -22,9 +22,9 @@ import { mockTemplate } from "./stubs/template";
 import { mockTranslations } from "./stubs/translations";
 
 class HaDemo extends HomeAssistantAppEl {
-  protected async _initialize() {
+  protected async _initializeHass() {
     const initial: Partial<MockHomeAssistant> = {
-      panelUrl: (this as any).panelUrl,
+      panelUrl: (this as any)._panelUrl,
       // Override updateHass so that the correct hass lifecycle methods are called
       updateHass: (hassUpdate: Partial<HomeAssistant>) =>
         this._updateHass(hassUpdate),