session-android/res/layout/mediarail_media_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="57dp"
    android:layout_height="57dp"
    android:layout_margin="2dp"
    android:animateLayoutChanges="true">

    <org.thoughtcrime.securesms.components.ThumbnailView
        android:id="@+id/rail_item_image"
        android:layout_width="56dp"
        android:layout_height="56dp"
        android:layout_gravity="center"
        android:background="@drawable/mediarail_media_outline"
        app:thumbnail_radius="5dp"/>

    <ImageView
        android:id="@+id/rail_item_outline"
        android:layout_width="57dp"
        android:layout_height="57dp"
        android:layout_gravity="center"
        android:src="@drawable/mediarail_media_outline"
        android:visibility="gone"
        tools:visibility="visible"/>

    <ImageView
        android:layout_width="56dp"
        android:layout_height="56dp"
        android:layout_gravity="center"
        android:src="@drawable/mediapicker_item_border_dark"/>

    <ImageView
        android:id="@+id/rail_item_caption"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="start|top"
        android:layout_marginStart="2dp"
        android:src="@drawable/ic_caption_28"
        android:visibility="gone"
        tools:visibility="visible"/>

    <ImageView
        android:id="@+id/rail_item_delete"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="end|top"
        android:layout_margin="1dp"
        android:src="@drawable/ic_x_28"
        android:visibility="gone"
        tools:visibility="visible"/>

</FrameLayout>