nextcloud-maps-client/app/src/main/res/drawable/floating_semitransparent_button_background.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/defaultBrandAlpha"/>
        </shape>
    </item>
</layer-list>