title: admob ads doesn't work when uploading the app on play store
body: <p>I am using google admob in the app when I used it with the test Id of the project it was working well but when I changed it to the live id the ads stop to come. 
  this is my java code :</p>
  
  <pre><code>MobileAds.initialize(this, getString(R.string.ad_mob_used_id));
  
      mInterstitialAd = new InterstitialAd(this);
      mInterstitialAd.setAdUnitId(getString(R.string.ad_mob_used_id));
      mInterstitialAd.loadAd(new AdRequest.Builder().build());
      mInterstitialAd.setAdListener(new AdListener(){
          @Override
          public void onAdLoaded() {
              super.onAdLoaded();
              mInterstitialAd.show();//TODO : check this
          }
      });
  </code></pre>
  
  <p>and this is the code in the manifest : </p>
  
  <pre><code>    &lt;meta-data
          android:name="com.google.android.gms.ads.APPLICATION_ID"
          android:value="@string/ad_mob_used_id"/&gt;
  </code></pre>
  
  <p>and this is the code in the strings : </p>
  
  <pre><code>&lt;string name="ad_mob_live_id"&gt;ca-app-pub-1283544791526621~9315704399&lt;/string&gt;
  &lt;string name="ad_mob_test_id"&gt;ca-app-pub-1283544791526621/5955878039&lt;/string&gt;
  
  &lt;!-- either live or debug --&gt;
  &lt;string name="ad_mob_used_id"&gt;ca-app-pub-1283544791526621~9315704399&lt;/string&gt;
  </code></pre>