Conversations/res/drawable/message_border.xml

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

    <corners android:radius="2dp" />

    <padding
        android:bottom="1.5dp"
        android:left="1.5dp"
        android:right="1.5dp"
        android:top="1.5dp" />

    <solid android:color="@color/divider" />

</shape>