Signal-Android/app/src/main/res/layout/conversation_item_update.xml

<?xml version="1.0" encoding="utf-8"?>
<org.thoughtcrime.securesms.conversation.ConversationUpdateItem
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/conversation_update_item"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/conversation_item_background"
    android:focusable="true"
    android:paddingStart="26dp"
    android:paddingEnd="26dp">

    <LinearLayout
        android:id="@+id/conversation_update_background"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginBottom="3dp"
        android:orientation="vertical"
        android:gravity="center"
        android:paddingTop="8dp"
        android:paddingBottom="8dp"
        android:paddingStart="10dp"
        android:paddingEnd="10dp">

        <org.thoughtcrime.securesms.components.emoji.EmojiTextView
            android:id="@+id/conversation_update_body"
            style="@style/Signal.Text.Preview"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:textColor="@color/conversation_item_update_text_color"
            tools:text="Gwen Stacy set the disappearing message timer to 1 hour" />

        <com.google.android.material.button.MaterialButton
            android:id="@+id/conversation_update_action"
            style="@style/Signal.Widget.Button.Small.Primary"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:visibility="gone"
            tools:text="Learn more"
            tools:visibility="visible" />

    </LinearLayout>

</org.thoughtcrime.securesms.conversation.ConversationUpdateItem>