app/src/main/res/drawable/custom_white_button.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:state_pressed="true"
        android:drawable="@android:color/darker_gray"
        />
    <item
        android:state_pressed="false"
        android:drawable="@android:color/transparent"
        />
</selector>