chore: Update license header to match the project

Author: LouisCAD

CrossAppLogin/Back/src/main/kotlin/com/infomaniak/core/crossapplogin/back/BaseCrossAppLoginService.kt

@@ -2,17 +2,18 @@
  * Infomaniak Core - Android
  * Copyright (C) 2025 Infomaniak Network SA
  *
- * 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
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
  *
- *     http://www.apache.org/licenses/LICENSE-2.0
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  *
- * 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.
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 @file:OptIn(ExperimentalSerializationApi::class)