Add json file

plugins/messageviewerconfigureplugins/scamsettings/CMakeLists.txt

 # SPDX-FileCopyrightText: 2021 Laurent Montel <montel@kde.org>
 # SPDX-License-Identifier: BSD-3-Clause
+
+if(BUILD_TESTING)
+    add_subdirectory(autotests)
+endif()

plugins/messageviewerconfigureplugins/scamsettings/messageviewer_scamconfiguresettingsplugin.json

+{
+    "KPlugin": {
+        "Description": "This plugin allows you to configure scam settings.",
+        "Name": "Scam Settings",
+        "Version": "1.0"
+    },
+    "X-KDE-MessageViewer-Configure-Order": "100"
+}