Twidere-App-Android-Twitter-Mastodon/twidere/src/main/res/drawable/shadow_user_banner_image.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">

    <gradient
        android:angle="270"
        android:centerColor="#00000000"
        android:endColor="#00000000"
        android:startColor="#80000000"/>

</shape>