tests/res/xml/appwidget_hidden.xml

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:minWidth="1dp"
    android:minHeight="1dp"
    android:updatePeriodMillis="86400000"
    android:initialLayout="@layout/test_layout_appwidget_blue"
    android:resizeMode="horizontal|vertical"
    android:widgetFeatures="hide_from_picker"
    android:widgetCategory="home_screen">
</appwidget-provider>