session-android/res/layout/media_preview_activity.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@color/gray95">

    <org.thoughtcrime.securesms.components.ZoomingImageView
               android:id="@+id/image"
               android:layout_width="match_parent"
               android:layout_height="match_parent"
               android:contentDescription="@string/media_preview_activity__image_content_description" />

    <org.thoughtcrime.securesms.video.VideoPlayer
            android:id="@+id/video_player"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:visibility="gone"/>

</RelativeLayout>