tests/ThemePlayground/res/layout/dialog_samples.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Copyright (C) 2018 The Android Open Source Project
  ~
  ~ Licensed under the Apache License, Version 2.0 (the "License");
  ~ you may not use this file except in compliance with the License.
  ~ You may obtain a copy of the License at
  ~
  ~      http://www.apache.org/licenses/LICENSE-2.0
  ~
  ~ Unless required by applicable law or agreed to in writing, software
  ~ distributed under the License is distributed on an "AS IS" BASIS,
  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ~ See the License for the specific language governing permissions and
  ~ limitations under the License
  -->

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/dialogLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <include layout="@layout/set_background"
             android:id="@+id/setBackground"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginTop="20dp"
             app:layout_constraintBottom_toTopOf="@+id/showDialogBT"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="parent"/>


    <Button
        android:id="@+id/showDialogBT"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show Dialog"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/showDialogWithCheckboxBT"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show Dialog With Checkbox"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/showDialogBT" />

    <Button
        android:id="@+id/showToast"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show Toast"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/showDialogWithCheckboxBT" />

    <include layout="@layout/menu_button"/>

</androidx.constraintlayout.widget.ConstraintLayout>