Add SPDX header

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

Author: AndyScherzinger

app/src/main/res/drawable/ic_rich_editing_grey600_24dp.xml

@@ -1,17 +1,9 @@
 <!--
-Copyright Andreas Gohr
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
+  ~ Nextcloud Notes - Android Client
+  ~
+  ~ SPDX-FileCopyrightText: 2021-2024 Nextcloud GmbH and Nextcloud contributors
+  ~ SPDX-FileCopyrightText: 2021 Andreas Gohr
+  ~ SPDX-License-Identifier: Apache-2.0
 -->
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
     android:width="24dp"