Remove Deprecated Notification Class

[sankhaKarunasekara]

File Name: FCMService.java

private Message.Builder getPreconfiguredMessageBuilder(PushNotificationRequest request) {
        AndroidConfig androidConfig = getAndroidConfig(request.getTopic());
        ApnsConfig apnsConfig = getApnsConfig(request.getTopic());
        return Message.builder()
                .setApnsConfig(apnsConfig).setAndroidConfig(androidConfig).setNotification(
                        new Notification(request.getTitle(), request.getMessage()));
    }

The Notification class in above method is deprecated, this method need to be replaced with more modern implementation.

good place to start: refer firebase-admin-java test files.