Threema-Android-mirror/app/src/main/res/drawable/shape_rounded_bottomsheet.xml

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

	<solid android:color="@color/dark_material_level3" />
	<corners
		android:topLeftRadius="16dp"
		android:topRightRadius="16dp" />

</shape>