title: Ads doesn't appear
body: <p>I have a libgdx game and I successfully added Admob ads to it. When I run it on my physical device using Android Studio it shows ads as I used my device as test device but when I send it to another device from my phone it didn't show ads. It only showed a black rectangle with no ads as I set adView background to black colour.</p>
  
  <p>My question is: should it be uploaded to the Google Play Store to show the ads or what?</p>
  
  <p>Here is my code:</p>
  
  <pre><code>protected AdView adView;
  
  @Override
  protected void onCreate (Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);       
  
      RelativeLayout layout = new RelativeLayout(this);
  
      AndroidApplicationConfiguration config = new AndroidApplicationConfiguration();
      View gameView = initializeForView(new GameMain(), config);
      layout.addView(gameView, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
  
      adView = new AdView(this);
      adView.setAdSize(AdSize.SMART_BANNER);
      adView.setVisibility(View.VISIBLE);
      AdRequest.Builder builder = new AdRequest.Builder();
      adView.loadAd(builder.build());
      adView.setBackgroundColor(0xff000000);
      adView.setAdUnitId("xxxxxxxxxxxxxxxxxxx");
  
      RelativeLayout.LayoutParams adParams = new RelativeLayout.LayoutParams( ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT    );
         adParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
      layout.addView(adView, adParams);
  
      setContentView(layout);
  }
  </code></pre>