data/res/layout/notification_template_messaging_group.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Copyright (C) 2016 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.internal.widget.MessagingGroup
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/status_bar_latest_event_content"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal" >
    <FrameLayout
        android:id="@+id/message_icon_container"
        android:layout_width="@dimen/conversation_content_start"
        android:layout_height="wrap_content">
        <ImageView
            android:layout_gravity="top|center_horizontal"
            android:id="@+id/message_icon"
            android:layout_width="@dimen/messaging_avatar_size"
            android:layout_height="@dimen/messaging_avatar_size"
            android:scaleType="centerCrop"
            android:importantForAccessibility="no" />
    </FrameLayout>
    <com.android.internal.widget.RemeasuringLinearLayout
        android:id="@+id/messaging_group_content_container"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:orientation="vertical">
        <com.android.internal.widget.ImageFloatingTextView
            android:id="@+id/message_name"
            style="@style/Widget.DeviceDefault.Notification.MessagingName"
            android:layout_width="wrap_content"
            android:textAlignment="viewStart"
        />
        <com.android.internal.widget.MessagingLinearLayout
            android:id="@+id/group_message_container"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/notification_text_margin_top"
            android:spacing="2dp" />
    </com.android.internal.widget.RemeasuringLinearLayout>
    <FrameLayout
        android:id="@+id/messaging_group_icon_container"
        android:layout_width="@dimen/messaging_avatar_size"
        android:layout_height="@dimen/messaging_avatar_size"
        android:layout_marginStart="12dp"
        android:visibility="gone"/>
    <FrameLayout
        android:id="@+id/messaging_group_sending_progress_container"
        android:layout_width="@dimen/messaging_group_sending_progress_size"
        android:layout_height="@dimen/messaging_avatar_size"
        android:layout_marginStart="12dp"
        android:layout_gravity="top"
        android:visibility="gone">
        <ProgressBar
            android:id="@+id/messaging_group_sending_progress"
            android:layout_height="@dimen/messaging_group_sending_progress_size"
            android:layout_width="@dimen/messaging_group_sending_progress_size"
            android:layout_gravity="center"
            android:indeterminate="true"
            style="?android:attr/progressBarStyleSmall" />
    </FrameLayout>
</com.android.internal.widget.MessagingGroup>