title: Admob ads not showing in the real device although its working on the Emulator
body: <p>I am having the Admob problem its working fine with test AppId and AdUnitId on emulator and real device.
      both the devices show the "Nice Job" test Ads</p>
  
  <p>After creating my AppId and My AdUnitId the emulator is showing next level ads and working
      but the real device don't show anything. no adview bar in the real device</p>
  
  <p>My codes are as below-</p>
  
  <p>build.gradle ModuleApp</p>
  
  <blockquote>
    <p>dependencies { 
        ...<br>
        implementation 'com.google.android.gms:play-services-ads:18.3.0'  }</p>
  </blockquote>
  
  <p>AndroidManifest.xml</p>
  
  <blockquote>
  <pre><code>&lt;application  
        ...         
       &lt;meta-data           android:name="com.google.android.gms.ads.APPLICATION_ID"             
        android:value="@string/xsAdmobMyAppId"/&gt;    
  &lt;/application&gt;
  </code></pre>
  </blockquote>
  
  <p>activity_current.xml</p>
  
  <pre><code>&lt;com.google.android.gms.ads.AdView
      android:id="@+id/adView"
  
      app:layout_constraintTop_toTopOf="parent"
      app:layout_constraintEnd_toEndOf="parent"
      app:layout_constraintStart_toStartOf="parent"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="center_horizontal"
  
      app:adSize="BANNER"
      app:adUnitId="@string/xsAdmobMyBannerUnitId"&gt;
  
  &lt;/com.google.android.gms.ads.AdView&gt;
  </code></pre>
  
  <p>CurrentActivity.java inside onCreate()</p>
  
  <pre><code>MobileAds.initialize(this, new OnInitializationCompleteListener() {
      @Override
      public void onInitializationComplete(InitializationStatus initializationStatus) {
      }
  });
  
  AdView mAdView = findViewById(R.id.adView);
  
  AdRequest adRequest = new AdRequest.Builder()
          .build();
  mAdView.loadAd(adRequest);
  </code></pre>
  
  <p>One more query:
  It is shown in the developers.google.com get started information to add the MobileAds.initialize{...}
  What is the requirement of this, as the app is working still working even if the code is not added.</p>
  
  <p>I found some similar questions on the web but didn't find/understand the proper solution.</p>