title: Having trouble getting Admob test banner to display on app
body: <p>I'm trying to implement Google Admob into my app but the test banner isn't even displaying. I've managed to get rid of all debug error messages but still get nothing being display. Could it be hiding in the background? This code is implemented in my OnCreate method after OpenGL initialization. Have followed the guides on Google to the letter. I'm stumped.</p>
  
  <pre><code>MobileAds.initialize(this, new OnInitializationCompleteListener() {
              @Override
              public void onInitializationComplete(InitializationStatus initializationStatus){}
          });
  
     List&lt;String&gt; testDeviceIds = Arrays.asList("8X126XD7X13XD3X8CXE0X2BXA1X67XDX");
          RequestConfiguration requestConfiguration
                  = new RequestConfiguration.Builder()
                  .setTestDeviceIds(testDeviceIds)
                  .setMaxAdContentRating(RequestConfiguration.MAX_AD_CONTENT_RATING_G)
                  .build();
          MobileAds.setRequestConfiguration(requestConfiguration);
  
  adView = new AdView(this);
          adView.setAdSize(AdSize.BANNER);
          adView.setAdUnitId("ca-app-pub-3940256099942544/6300978111");       // ANDROID TEST ID
          AdRequest adrequest = new AdRequest.Builder().build();
          adView.loadAd(adrequest);
  </code></pre>
  
  <p>I've run adrequest.isTestDevice(this) and it comes back as TRUE so my device seems to be working. I'm testing on a real device (Sony Xperia XZ). Any ideas??</p>