styles.xml

<!-- res/values-night/styles.xml -->
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="navigationBarColor">@android:color/black</color>
    <color name="navigationIconColor">@android:color/white</color>

    <style name="AppTheme.NoActionBar" parent="Theme.AppCompat.DayNight.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
        <item name="android:background">@null</item>
        <item name="android:navigationBarColor">@color/navigationBarColor</item>
    </style>
</resources>

<!-- res/values-v27/styles.xml -->
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="AppTheme.NoActionBar" parent="Theme.AppCompat.DayNight.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
        <item name="android:background">@null</item>
        <item name="android:navigationBarColor">@color/navigationBarColor</item>
        <item name="android:windowLightNavigationBar">true</item>
    </style>
</resources>

<!-- res/values-night-v27/styles.xml -->
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="AppTheme.NoActionBar" parent="Theme.AppCompat.DayNight.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
        <item name="android:background">@null</item>
        <item name="android:navigationBarColor">@color/navigationBarColor</item>
        <item name="android:windowLightNavigationBar">false</item>
    </style>
</resources>