[Bug]: Fix for plugin_cmf_perm_activityview permission issue (#561)

Co-authored-by: Ji Jia Jia <[email protected]>

Author: rliebi

src/Resources/public/js/ActivityView.js

@@ -14,9 +14,12 @@
 
 var ActivityView = pimcore.registerNS("pimcore.plugin.customermanagementframework.ActivityView");
 
-ActivityView.config = {
-    PERMISSION: "plugin_cmf_perm_activityview"
-};
+Object.defineProperty(ActivityView,'config', {
+    value: {
+        PERMISSION: "plugin_cmf_perm_activityview"
+    },
+    writable: false,
+});
 
 ActivityView.ActivityTab = Class.create({