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

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/preference_divider">

    <FrameLayout
        android:id="@+id/video_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/message_details_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager" />
</FrameLayout>