Signal-Android/app/src/main/res/drawable/show_more.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="oval">
            <solid android:color="@color/signal_background_secondary" />
            <padding android:right="8dp" android:bottom="8dp" android:left="8dp" android:top="8dp" />
        </shape>
    </item>
    <item android:drawable="@drawable/ic_chevron_down_icon_20" />
</layer-list>