res/layout/car_bottom_system_bar_unprovisioned.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
  -->

<com.android.systemui.car.systembar.CarSystemBarView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:systemui="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/system_bar_background"
    android:orientation="vertical">

    <LinearLayout
        android:id="@+id/nav_buttons"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:paddingStart="@*android:dimen/car_padding_5"
        android:paddingEnd="@*android:dimen/car_padding_5">

        <com.android.systemui.car.systembar.CarSystemBarButton
            android:id="@+id/home"
            android:layout_width="@*android:dimen/car_touch_target_size"
            android:layout_height="match_parent"
            android:background="?android:attr/selectableItemBackground"
            systemui:icon="@drawable/car_ic_overview"
            systemui:intent="intent:#Intent;action=android.intent.action.MAIN;category=android.intent.category.HOME;launchFlags=0x14000000;end"
            systemui:selectedIcon="@drawable/car_ic_overview_selected"
            systemui:highlightWhenSelected="true"
        />
    </LinearLayout>
</com.android.systemui.car.systembar.CarSystemBarView>