libs/WindowManager/Shell/res/layout/caption_window_decoration.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Copyright (C) 2022 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.
  -->
<com.android.wm.shell.windowdecor.WindowDecorLinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/caption"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="end"
    android:background="@drawable/decor_caption_title">
    <Button
        android:id="@+id/maximize_window"
        android:layout_width="32dp"
        android:layout_height="32dp"
        android:layout_margin="5dp"
        android:padding="4dp"
        android:layout_gravity="center_vertical|end"
        android:contentDescription="@string/maximize_button_text"
        android:background="@drawable/decor_maximize_button_dark"
        android:duplicateParentState="true"/>
    <Button
        android:id="@+id/close_window"
        android:layout_width="32dp"
        android:layout_height="32dp"
        android:layout_margin="5dp"
        android:padding="4dp"
        android:layout_gravity="center_vertical|end"
        android:contentDescription="@string/close_button_text"
        android:background="@drawable/decor_close_button_dark"
        android:duplicateParentState="true"/>
</com.android.wm.shell.windowdecor.WindowDecorLinearLayout>