title: kotlin admob ad not shown
body: <p>I try to add adMob Intersiciel in app in Kotlin
  I ve follow the docs (<a href="https://developers.google.com/admob/android/quick-start" rel="nofollow noreferrer">https://developers.google.com/admob/android/quick-start</a> and <a href="https://developers.google.com/admob/android/interstitial#kotlin_1" rel="nofollow noreferrer">https://developers.google.com/admob/android/interstitial#kotlin_1</a>)
  But the ad is not shown(But no any error on the app in the emulator) So I need of your help.
  I think the problem is come from &quot;Set the FullScreenContentCallback&quot;in the doc. Could you confirm that the code need to be in a function eg loadAd and &quot;Show the ad&quot;in a function showAd&quot;which to be call when needed&gt; Or maybe do you know a tutoriel to find the solution to my problem. Thanks</p>