Signal-Android/res/drawable/compose_background_dark.xml

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

    <stroke
        android:width="1dp"
        android:color="@color/core_grey_75" />

    <solid
        android:color="@color/core_grey_90" />

    <corners
        android:radius="20dp" />

</shape>