dev/integration_tests/non_nullable/android/app/src/main/res/values/styles.xml

<!-- Copyright 2014 The Flutter Authors. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file. -->

<resources>
    <!-- Theme applied to the Android Window as soon as the process has started.
         This theme determines the color of the Android Window while your
         Flutter UI initializes, as well as behind your Flutter UI while its
         running.

         This Theme is only used starting with V2 of Flutter's Android embedding. -->
    <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
        <item name="android:windowBackground">@android:color/white</item>
    </style>
</resources>