conversations-classic/src/main/res/layout/activity_start_conversation.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <include android:id="@+id/toolbar"
            layout="@layout/toolbar" />
        <android.support.design.widget.TabLayout
            android:id="@+id/tab_layout"
            android:layout_below="@id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/colorPrimary"
            android:minHeight="?attr/actionBarSize"
            android:elevation="@dimen/toolbar_elevation"
            app:tabMode="fixed"
            app:tabGravity="fill"
            app:tabTextColor="@color/white70"
            app:tabSelectedTextColor="@color/white"
            app:tabIndicatorColor="@color/white87"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />
        <android.support.v4.view.ViewPager
            android:id="@+id/start_conversation_view_pager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_below="@id/tab_layout"
            android:background="?attr/color_background_primary"/>
        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentEnd="true"
            app:backgroundTint="?colorPrimary"
            android:layout_alignParentRight="true"
            android:layout_alignParentBottom="true"
            android:src="?attr/icon_add_person"
            android:layout_margin="16dp" />
    </RelativeLayout>
</layout>