change walkthrough imagery to Bing

the old esri layer does not seem to be available anymore

CHANGELOG.md

@@ -60,6 +60,7 @@ _Breaking developer changes, which may affect downstream projects or sites that
 #### :earth_asia: Localization
 #### :hourglass: Performance
 #### :mortar_board: Walkthrough / Help
+* Change background imagery of walkthrough tutorial to Bing (the previous source is not available anymore)
 #### :rocket: Presets
 * Suggest housenumber/housename values from surrounding areas ([#10946])
 #### :hammer: Development

modules/ui/intro/intro.js

@@ -41,7 +41,7 @@ const chapterFlow = [
 
 
 export function uiIntro(context) {
-  const INTRO_IMAGERY = 'EsriWorldImageryClarity';
+  const INTRO_IMAGERY = 'Bing';
   let _introGraph = {};
   let _currChapter;