This is the fix for the enrollment error occurred when a user enrols android device to EMM 2.2.0 in FCM enabled environment if whitelist policy is enforced.

Please find the GitHub issue from [1]

[1]: https://github.com/wso2/product-iots/issues/1827

components/device-mgt-extensions/org.wso2.carbon.device.mgt.extensions.push.notification.provider.fcm/src/main/java/org/wso2/carbon/device/mgt/extensions/push/notification/provider/fcm/FCMNotificationStrategy.java

@@ -64,7 +64,9 @@ public class FCMNotificationStrategy implements NotificationStrategy {
             if (NOTIFIER_TYPE_FCM.equals(config.getType())) {
                 Device device = FCMDataHolder.getInstance().getDeviceManagementProviderService()
                         .getDeviceWithTypeProperties(ctx.getDeviceId());
-                this.sendWakeUpCall(ctx.getOperation().getCode(), device);
+                if(getFCMToken(device.getProperties()) != null) {
+                    this.sendWakeUpCall(ctx.getOperation().getCode(), device);
+                }
             } else {
                 if (log.isDebugEnabled()) {
                     log.debug("Not using FCM notifier as notifier type is set to " + config.getType() +