message: fix(keyboard): keyboardevent code
  In iOS device `ev.detail` is `undefined` from KeyboardEvent.
  Device: iPhoneX
diff: @@ -138,7 +138,7 @@ Detecting the presence of an on-screen keyboard is useful for adjusting the posi
  ```javascript
  window.addEventListener('ionKeyboardDidShow', ev => {
  - const { keyboardHeight } = ev.detail;
  + const { keyboardHeight } = ev;
  // Do something with the keyboard height such as translating an input above the keyboard.
  });
  @@ -156,7 +156,7 @@ import { Platform } from '@ionic/angular';
  constructor(private platform: Platform) {
  this.platform.keyboardDidShow.subscribe(ev => {
  - const { keyboardHeight } = ev.detail;
  + const { keyboardHeight } = ev;
  // Do something with the keyboard height such as translating an input above the keyboard.
  });
  