title: error: unknown element <intent-filter> found after upgrading to android 3.1
body: <p>Today I upgraded to Android Studio 3.1.4 and I have the first error </p>
  
  <pre><code>The option 'android.enableAapt2' is deprecated and should not be used anymore.
  Use 'android.enableAapt2=true' to remove this warning.
  It will be removed at the end of 2018..
  </code></pre>
  
  <p>Then I change the <code>android.enableAapt2</code> to true as it suggests. </p>
  
  <p>After that I have new error AAPT2 error</p>
  
  <pre><code>error: unknown element &lt;intent-filter&gt; found.
  Message{kind=ERROR, text=error: unknown element &lt;intent-filter&gt; found., sources=[C:\FILE\Android Studio\UltraGreek\UltraGreekv.4.7\app\build\intermediates\manifests\full\debug\AndroidManifest.xml:37], original message=, tool name=Optional.of(AAPT)}
  </code></pre>
  
  <p>My manifest in app/srs/main/AndroidManifest.xml is </p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
            package="com.ultragreek.ultragreek"&gt;
  
      &lt;uses-permission android:name="android.permission.INTERNET"/&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/&gt;
  
      &lt;application
          android:allowBackup="true"
          android:icon="@drawable/ultrasidelogo"
          android:label="@string/app_name"
          android:roundIcon="@mipmap/ic_launcher_round"
          android:supportsRtl="true"
          android:theme="@style/AppTheme"&gt;
          &lt;activity
              android:name=".MainActivity"
              android:label="@string/app_name"
              android:theme="@style/AppTheme.NoActionBar"&gt;
              &lt;intent-filter&gt;
                  &lt;action android:name="android.intent.action.MAIN"/&gt;
  
                  &lt;category android:name="android.intent.category.LAUNCHER"/&gt;
              &lt;/intent-filter&gt;
          &lt;/activity&gt;
          &lt;activity android:name=".ActivitySecond"/&gt;
  
          &lt;activity android:name=".ActivityAbout"/&gt;
          &lt;activity android:name=".WebViewer"/&gt;
  
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.SEND"/&gt;
  
              &lt;category android:name="android.intent.category.DEFAULT"/&gt;
  
              &lt;data android:mimeType="text/plain"/&gt;
          &lt;/intent-filter&gt;
  
          &lt;activity
              android:name=".ActivityStats"
              android:label="Στατιστικά"&gt;
          &lt;/activity&gt;
      &lt;/application&gt;
  
  &lt;/manifest&gt;
  </code></pre>