fix(angular): warnings are no longer generated when running tests with ng test (#23292)

resolves #19926

Co-authored-by: Sean Wu <seanwu1105@users.noreply.github.com>

Author: liamdebeasi

angular/src/app-initialize.ts

@@ -5,16 +5,10 @@ import { Config } from './providers/config';
 import { IonicWindow } from './types/interfaces';
 import { raf } from './util/util';
 
-let didInitialize = false;
-
 export const appInitialize = (config: Config, doc: Document, zone: NgZone) => {
   return (): any => {
     const win: IonicWindow | undefined = doc.defaultView as any;
     if (win && typeof (window as any) !== 'undefined') {
-      if (didInitialize) {
-        console.warn('Ionic Angular was already initialized. Make sure IonicModule.forRoot() is just called once.');
-      }
-      didInitialize = true;
       const Ionic = win.Ionic = win.Ionic || {};
 
       Ionic.config = {