item_gallery.xml

<?xml version="1.0" encoding="utf-8"?>
<com.illuzor.lesson.wallpapers.ui.SquareConstraintLayout 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="0dp">

    <ImageView
        android:id="@+id/iv_preview"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:scaleType="centerCrop"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</com.illuzor.lesson.wallpapers.ui.SquareConstraintLayout>