title: Flutter firebase_admob does not display Ad in testdevice
body: <p>I cannot display my ad unit on my device in test app.</p>
  
  <p>I'am using the firebase_admob 0.9.1+1 plugin</p>
  
  <p>This is the code I use :</p>
  
  <pre><code>import 'package:firebase_admob/firebase_admob.dart';
  
  Future initAppAds() async {
    //Récupère du coup le bon ID selon si je suis sous IOS ou Android
    print(getAppId());
    await FirebaseAdMob.instance.initialize(appId: 'ca-app-pub-xxxxxxxxMyAppIdxxxxxxxxxxx');
  
  }
  
  
  Future launchAds() async {
    print("launchAds");
    print(getInterstitialId());
    MobileAdTargetingInfo targetingInfo = MobileAdTargetingInfo(
      nonPersonalizedAds: true, 
    );
  
  
    InterstitialAd myInterstitial = InterstitialAd(
      adUnitId: 'ca-app-pub-xxxxxxxxxxxxx/xxxxMyAdBloc',
      targetingInfo: targetingInfo, //Info de l'utilisateur
      listener: (MobileAdEvent event) {
        print("InterstitialAd event is $event");
      },
    );
  
    await myInterstitial.load();
    await myInterstitial.show(
      anchorType: AnchorType.bottom,
      anchorOffset: 0.0,
      horizontalCenterOffset: 0.0
    );
  
  }
  </code></pre>
  
  <p>Here is the log I get :</p>
  
  <pre><code>2866-2866/com.fabien.movizz I/Ads: Use RequestConfiguration.Builder().setTestDeviceIds(Arrays.asList("6C11832B439BDE4C399171C8D4CC6515") to get test ads on this device.
  6769-3457/? W/Ads: App does not have the required permissions to get location
  6769-3539/? I/Ads: SDK version: afma-sdk-a-v20088999.15301000.1
  6769-3539/? W/Ads: Received error HTTP response code: 400
  2866-2866/com.fabien.movizz I/Ads: Ad failed to load : 0
  </code></pre>
  
  <p>So I specified the ID of my device like this:</p>
  
  <pre><code>  MobileAdTargetingInfo targetingInfo = MobileAdTargetingInfo(
      nonPersonalizedAds: true,
      testDevices: &lt;String&gt;["6C11832B439BDE4C399171C8D4CC6515"],
    );
  </code></pre>
  
  <p>But the ad still doesn't appear. Here is the log I get :</p>
  
  <pre><code>2866-2866/com.fabien.movizz I/Ads: This request is sent from a test device.
  6769-3380/? W/Ads: App does not have the required permissions to get location
  6769-3457/? I/Ads: SDK version: afma-sdk-a-v20088999.15301000.1
  6769-3457/? W/Ads: Received error HTTP response code: 400
  2866-2866/com.fabien.movizz I/Ads: Ad failed to load : 0
  </code></pre>
  
  <p>If I use a test advertisement <a href="https://developers.google.com/admob/android/test-ads" rel="nofollow noreferrer">provided by Google</a>, the advertisement works well and here is the log I get:</p>
  
  <pre><code>2866-2866/com.fabien.movizz I/Ads: This request is sent from a test device.
  6769-3539/? W/Ads: App does not have the required permissions to get location
  6769-5440/? I/Ads: SDK version: afma-sdk-a-v20088999.15301000.1
  </code></pre>
  
  <p>What's wrong with my ad unit? I created it 2 days ago, did I wait long enough for it to appear?</p>
  
  <p>Thanks for your help ;)</p>
  
  <p><a href="https://i.stack.imgur.com/8rfp3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8rfp3.png" alt="enter image description here"></a></p>
  
  <p>Here is my flutter doctor :
  <a href="https://i.stack.imgur.com/i0528.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/i0528.png" alt="enter image description here"></a></p>