skopeo: Add oniro-specific configuration

The most notable change is that we use the application partition for the
root's graphroot. We also explicitly set the storage driver and runtime
directory.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-oniro-core/recipes-containers/skopeo/skopeo/storage.conf

+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+[storage]
+driver = "overlay"
+runroot = "/run/containers/storage"
+graphroot="/run/mount/appdata/user-data/containers/root-rootuser"

meta-oniro-core/recipes-containers/skopeo/skopeo_%.bbappend

+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"