Add license

Signed-off-by: Arthur-GYT <a.gayot@posteo.com>

app/src/main/res/resources.properties

@@ -1 +1,9 @@
+#
+# Nextcloud - Android Client
+#
+# SPDX-FileCopyrightText: 2024 Arthur-GYT <a.gayot@posteo.com>
+# SPDX-FileCopyrightText: 2024 Nextcloud GmbH
+# SPDX-License-Identifier: AGPL-3.0-or-later
+#
+
 unqualifiedResLocale=en-US