examples/android/res/values/styles.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <style name="AppRTCDemoActivityTheme" parent="android:Theme.Black">
    <item name="android:windowActionBar">false</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:windowNoTitle">true</item>
  </style>
</resources>