message: fix reactnative isOnline check
diff: +import { CoreUtils } from '@microsoft/applicationinsights-core-js';
  +
  /**
  * @description Monitors browser for offline events
  * @export default - Offline: Static instance of OfflineListener
  @@ -45,7 +47,7 @@ export class OfflineListener {
  public isOnline(): boolean {
  if (this.isListening) {
  return this._onlineStatus
  - } else if (navigator) {
  + } else if (navigator && !CoreUtils.isNullOrUndefined(navigator.onLine)) { // navigator.onLine is undefined in react-native
  return navigator.onLine;
  } else {
  // Cannot determine online status - report as online
  