res/drawable/list_divider.xml

<?xml version="1.0" encoding="utf-8"?>
<inset
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:insetLeft="@dimen/list_divider_inset"
    android:insetRight="@dimen/list_divider_inset">
    <shape android:shape="rectangle">
        <solid android:color="@color/divider_color"/>
        <size android:height="@dimen/list_divider_height"/>
    </shape>
</inset>