IssueTracker

Component used: core-splashscreen
Version used: 1.0.0-alpha01
Devices/Android versions reproduced on: API 31

It seems the style is applied based on a fix from https://issuetracker.google.com/issues/196273921, but it breaks the automatic colour contrast change of the navigation bar and doesn't apply the scrim behind 3 button navigation. Important to note, this is NOT an issue when using the gesture based navigation. Seems to only impact 2 & 3 button navigation.

Follow these steps to reproduce.

1. Create a new project (I used a bottom tab project for my base)
2. Implement basic instructions for SplashScreen (have some code snippits below)
3. Implement edge-to-edge as in this document https://developer.android.com/develop/ui/views/layout/edge-to-edge#java If your activity has a dark background, you'd think to set android:windowLightNavigationBar to false, but setting this attribute will stop the automatic contrast feature for the bottom buttons.

Here is some code to kickstart.

themes.xml

<resources xmlns:tools="http://schemas.android.com/tools">
    <!-- Base application theme. -->
    <style name="Theme.MyApplication" parent="Theme.AppCompat.DayNight.NoActionBar">
        <!-- Primary brand color. -->
        <item name="colorPrimary">@color/purple_500</item>
        <item name="colorPrimaryVariant">@color/purple_700</item>
        <item name="colorOnPrimary">@color/white</item>
        <!-- Secondary brand color. -->
        <item name="colorSecondary">@color/teal_200</item>
        <item name="colorSecondaryVariant">@color/teal_700</item>
        <item name="colorOnSecondary">@color/black</item>
        <!-- Status bar color. -->
        <item name="android:statusBarColor">?attr/colorPrimaryVariant</item>
        <item name="android:navigationBarColor">
            @android:color/transparent
        </item>
        <item name="android:windowLightNavigationBar">true</item>
        
    </style>

    <style name="Theme.App.Starting" parent="Theme.SplashScreen">
        <item name="windowSplashScreenBackground">@color/splashscreen_bg</item>
        <item name="postSplashScreenTheme">@style/Theme.MyApplication</item>

    </style>
</resources>

MainActivity

SplashScreen splashScreen = SplashScreen.installSplashScreen(this);
        super.onCreate(savedInstanceState);
        WindowCompat.setDecorFitsSystemWindows(getWindow(), false);

        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        splashScreen.setOnExitAnimationListener(splashScreenViewProvider -> {
            final View splashScreenView = splashScreenViewProvider.getView();

            splashScreenView
                    .animate()
                    .setDuration(0)
                    // Hack to avoid automatic layout transitions
                    .setStartDelay(Math.min(0, 0))
                    .alpha(0.0f)
                    .setInterpolator(new AccelerateInterpolator())
                    .setListener(new AnimatorListenerAdapter() {
                        @Override
                        public void onAnimationEnd(Animator animation) {
                            super.onAnimationEnd(animation);
                            splashScreenViewProvider.remove();
                        }
                    }).start();
        });