[presets] add steamos files

presets/steam/steamos/bin/steamos-boot-install

@@ -0,0 +1,18 @@
+#!/bin/bash
+# -*- mode: sh; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
+# vim: et sts=4 sw=4
+
+#  SPDX-License-Identifier: LGPL-2.1+
+#
+#  Copyright © 2020-2021 Collabora Ltd.
+#  Copyright © 2020-2021 Valve Corporation.
+#
+#  This file is part of steamos-customizations.
+#
+#  steamos-customizations is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public License as
+#  published by the Free Software Foundation; either version 2.1 of the License,
+#  or (at your option) any later version.
+
+# This is a simple wrapper that provides backwards compatibility to the renamed steamos-finalize-install
+source "${BASH_SOURCE%/*}"/steamos-finalize-install "$@";