tests/TransitionTests/res/layout/button_template.xml

<?xml version="1.0" encoding="utf-8"?>

<Button xmlns:android="http://schemas.android.com/apk/res/android"
              android:onClick="sendMessage"
              android:id="@+id/button"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content">

</Button>