tests/res/layout/test_layout_appwidget_blue.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/content"
    android:orientation="vertical"
    android:background="#FF0000FF"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />