title: Xamarin Forms Android project won't deploy if I have application tag in Manifest
body: <p>I have a Xamarin Forms project and is trying to add Admob using this <a href="https://www.xamarinhelp.com/admob-xamarin-forms-display-google-ads-mobile-app/" rel="nofollow noreferrer">article</a> and <a href="https://docs.microsoft.com/en-us/answers/questions/388225/xamarinforms-39unable-to-get-provider-comgoogleand.html" rel="nofollow noreferrer">this</a>.</p>
  <p>One of them involve declaring the <code>AdActivity</code> in the manifest:</p>
  <pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
  &lt;manifest xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot; android:versionCode=&quot;1&quot; android:versionName=&quot;1.0&quot; package=&quot;com.example.name&quot; android:installLocation=&quot;auto&quot;&gt;
      &lt;uses-sdk android:minSdkVersion=&quot;21&quot; android:targetSdkVersion=&quot;30&quot; /&gt;
      &lt;application android:label=&quot;Example.Android&quot; android:theme=&quot;@style/MainTheme&quot;&gt;&lt;/application&gt;
      &lt;uses-permission android:name=&quot;android.permission.ACCESS_NETWORK_STATE&quot; /&gt;
      &lt;uses-permission android:name=&quot;android.permission.INTERNET&quot; /&gt;
  
      &lt;application android:label=&quot;@string/appName&quot; android:theme=&quot;@style/MainTheme&quot;&gt;
          &lt;meta-data android:name=&quot;com.google.android.gms.ads.APPLICATION_ID&quot; android:value=&quot;&quot; /&gt;
          &lt;activity android:name=&quot;com.google.android.gms.ads.AdActivity&quot; android:configChanges=&quot;keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize&quot; android:theme=&quot;@android:style/Theme.Translucent&quot; /&gt;
      &lt;/application&gt;
  &lt;/manifest&gt;
  </code></pre>
  <p>However after I add the <code>&lt;application&gt;</code> tag, I couldn't deploy anymore (the Build is still successful). At first an error shows up asking me to disable &quot;Use Fast Deployment&quot; but after I disabled it, nothing shows up anymore.</p>
  <p>I have tried to only have an empty <code>&lt;application&gt;&lt;/application&gt;</code> tag, the problem is still there. Removing it would help the app deployed and run but I encounter an exception that <code>AdActivity</code> is not declared obviously. I suspected it could be duplicate declaration so in my <code>MainActivity</code> file I removed every declarative attribute and only write <code>[Activity]</code> but the problem is still there.</p>
  <p>What is the problem? I think I can solve it either by:</p>
  <ul>
  <li><p>Somehow declare an <code>[Activity]</code> attribute on <code>AdActivity</code>. Unfortunately it's sealed.</p>
  </li>
  <li><p>Add <code>&lt;application&gt;</code> tag. Seem like everyone was able to do that without this problem.</p>
  </li>
  </ul>