title: Google maps only load the first time, second time it is gray
body: <p>I have created an Ionic 2 / Angular 2 App. I have integrated Google Maps and it works fine. However the second time the Google Maps appears completely gray. I have searched the internet and tried different solutions to solve it. However, none of the solutions below work:
  - google.maps.event.trigger(this.map, 'resize');
  - google.maps.event.clearInstanceListeners / this.map.detach(); / this.marker.setMap(null); </p>
  
  <p>When I resize the view in chrome then the maps which appeared in gray is suddenly shown. So how can I trigger this resize manually. I hope you can help.</p>
  
  <p>My code can be found here <a href="https://github.com/marinusgeuze/metjekindnaarbuiten" rel="noreferrer">https://github.com/marinusgeuze/metjekindnaarbuiten</a>.</p>
  
  <p>Best regards,
  Marinus Geuze</p>
  
  <p>===========================================</p>
  
  <p>Issue is solved by adding next line of code: 
  setTimeout(() => google.maps.event.trigger(this.map, 'resize'), 600);</p>