sample/src/main/res/layout/empty_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/finish"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Finish" />

</FrameLayout>