samples/SupportWearDemos/src/main/res/layout/alert_dialog_demo.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Copyright 2017 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.
  -->

<android.support.wear.widget.BoxInsetLayout
    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">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        app:boxedEdges="all">

        <Button
            android:id="@+id/v7_dialog_button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Show V7 dialog"/>

        <Button
            android:id="@+id/framework_dialog_button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Show Framework dialog"/>
    </LinearLayout>

</android.support.wear.widget.BoxInsetLayout>