session-android/res/layout/conversation_item_header.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:paddingTop="20dp"
    android:paddingBottom="21dp"
    android:paddingLeft="28dp"
    android:paddingRight="28dp">

    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        style="@style/Signal.Text.Caption"
        android:textColor="?conversation_item_update_text_color"
        android:textAllCaps="true"
        tools:text="March 1, 2015" />

</LinearLayout>