wulkanowy-mod/app/src/main/res/drawable/layer_splash_background.xml

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape>
            <solid android:color="@color/colorPrimaryDark" />
        </shape>
    </item>
    <item>
        <bitmap
            android:gravity="left|right|top|bottom"
            android:src="@drawable/img_splash_logo" />
    </item>
</layer-list>