samples/VirtualDeviceManager/host/res/layout/activity_settings.xml

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

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/main_tool_bar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        android:elevation="4dp"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
        app:navigationIcon="?homeAsUpIndicator"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/settings_fragment_container"
        android:name="com.example.android.vdmdemo.host.SettingsActivity$SettingsFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>