Quelle  item_send_media_add.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:id="@+id/content_frame"
    android:layout_width="@dimen/send_media_item_width"
    android:layout_height="@dimen/send_media_item_width"
    android:foreground="?attr/selectableItemBackground"
    android:background="@drawable/shape_add_media_item_bg">

    <ImageView
        android:id="@+id/thumbnail_view"
        android:layout_width="36dp"
        android:layout_height="36dp"
        android:layout_gravity="center"
        android:adjustViewBounds="false"
        android:contentDescription="@string/add_attachment"
        app:srcCompat="@drawable/ic_add_white_24dp"
        app:tint="@android:color/white" />

</FrameLayout>