Samples/ActivityFeed/activityfeed/src/main/res/layout/activity_feed.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@color/white">

    <EditText
        android:id="@+id/messageEdit"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_alignParentBottom="true"
        android:hint="Message"
        android:layout_alignBottom="@+id/chatSendButton"
        android:layout_toStartOf="@+id/chatSendButton"
        android:paddingEnd="10dp"
        android:paddingStart="10dp" />

    <Button
        android:id="@+id/chatSendButton"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentEnd="true"
        android:background="@color/colorPrimary"
        android:text="Send"
        android:textColor="@color/background_material_light"
        android:layout_alignParentTop="false"
        android:layout_alignParentStart="false" />

    <ListView
        android:id="@+id/messagesContainer"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentStart="false"
        android:layout_alignParentTop="false"
        android:layout_marginBottom="50dp"
        android:listSelector="@android:color/transparent"
        android:transcriptMode="alwaysScroll"
        android:divider="@null"
        android:background="@color/switch_thumb_normal_material_light"
        android:paddingBottom="10dp"
        android:stackFromBottom="true" />

</RelativeLayout>