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

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".activities.FollowActivity"
    android:background="@color/lightBlue">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/followUsernameText"
        android:minWidth="250dp"
        android:background="@android:color/white"
        android:height="40dp"
        android:layout_marginTop="70dp"
        android:hint="Username"
        android:paddingStart="10dp"
        android:singleLine="true"
        android:minLines="1"
        android:maxLines="1"
        android:minHeight="30dp"
        android:inputType="textPersonName"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:paddingEnd="10dp"
        android:maxWidth="250dp" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Add Follower"
        android:id="@+id/addFollowerButton"
        android:minWidth="250dp"
        android:background="@color/colorPrimary"
        android:textColor="@android:color/white"
        android:layout_below="@+id/followUsernameText"
        android:layout_alignStart="@+id/followUsernameText"
        android:layout_marginTop="30dp" />
</RelativeLayout>