apps/tv/SetupValidation/app/src/main/res/values/styles.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <style name="AppTheme" parent="@style/Theme.Leanback">
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:windowIsTranslucent">true</item>
        <item name="android:windowShowWallpaper">false</item>
    </style>
    
    <style name="AppThemeOpaque" parent="@style/Theme.Leanback">
        <item name="android:windowBackground">@android:color/holo_blue_light</item>
    </style>

</resources>