I upgrade notification module from GCM to FCM and release to 'Appstore' and 'playstore'. Issue is that updated App from old version device is receiving duplicated message. But delete app and reinstall it's ok just receive one message.
I found reason is older gcm token is still activated even app updated. one app has two activated token(one is gcm,another is fcm)
older gcm token
d3-b3LP9_mU:APA91bHMJkNZwJdt8R1beKy5B4T....
newer fcm token
d3-b3LP9_mU:APA91bEDC5Y4gqp3V9xyU.......
How can i disable older gcm token???
