Nature_Wallpaper/app/src/main/res/drawable/gradient_top.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:startColor="#80000000"
        android:endColor="#00000000"
        android:angle="270" />
</shape>