add license header and empty line at file end

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

app/src/main/java/com/nextcloud/talk/utils/UserIdUtils.kt

@@ -1,3 +1,23 @@
+/*
+ * Nextcloud Talk application
+ *
+ * @author Andy Scherzinger
+ * Copyright (C) 2022 Andy Scherzinger <info@andy-scherzinger.de>
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 package com.nextcloud.talk.utils
 
 import com.nextcloud.talk.data.user.model.User
@@ -12,4 +32,4 @@ object UserIdUtils {
             NO_ID
         }
     }
-}
+}