session-android/res/layout/media_preview_album_rail_item.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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:animateLayoutChanges="true">

    <org.thoughtcrime.securesms.components.ThumbnailView
        android:id="@+id/rail_item_image"
        android:layout_width="56dp"
        android:layout_height="56dp"
        android:layout_margin="2dp"
        android:padding="2dp"
        android:background="@drawable/media_rail_item_background"
        app:thumbnail_radius="0dp"/>

    <ImageView
        android:layout_width="52dp"
        android:layout_height="52dp"
        android:layout_gravity="center"
        android:src="@drawable/mediapicker_item_border_dark"/>

    <ImageView
        android:id="@+id/rail_item_delete"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right|end|top"
        android:src="@drawable/ic_x_circle"
        android:elevation="8dp"
        android:visibility="gone"
        tools:visibility="visible"/>

</FrameLayout>