[Trunk | Notificaton Service]:
1. NotificationConfiguration.java: [Bug fix] Commented @PropertySources (a library service should not set properties locally, but parent service is responsible for that).
2. NotificationController.java: For method "getAllNotifications()" (/all), set @PreAuthorize to PORTAL_ADMIN (instead of REGISTERED_USER) (used for testing).
3. NotificationService.java: Comment @Scheduled(cron = "0 0 0 1/1 * ?") method "deleteNotifications()" and never delete old notifications.
4. notification.properties: Commented properties - set in dnet-override.properties file.