packages/SystemUI/res/layout/system_icons.xml

<?xml version="1.0" encoding="utf-8"?><!--
  ~ Copyright (C) 2014 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
  -->

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/system_icons"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:gravity="center_vertical">

    <com.android.systemui.statusbar.AlphaOptimizedLinearLayout android:id="@+id/statusIcons"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:gravity="center_vertical"
        android:orientation="horizontal"/>

    <include layout="@layout/signal_cluster_view"
        android:id="@+id/signal_cluster"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="2dp"/>

    <!-- battery must be padded below to match assets -->
    <com.android.systemui.BatteryMeterView android:id="@+id/battery"
        android:layout_height="16dp"
        android:layout_width="10.5dp"
        android:layout_marginBottom="0.33dp"
        android:layout_marginStart="4dip"/>
</LinearLayout>