Advanced Android in Kotlin: Firebase Messaging 1.2 [Step #][description]

[hhyeok1026]

Describe the problem
A clear and concise description of what the problem is.

The following error lint occurs in MyFirebaseMessagingService.kt file,
The build fails.
=>
'onMessageReceived' overrides nothing
'onNewToken' overrides nothing

In my case, I changed fcm message to the latest version,

When looking at the FirebaseMessagingService file that inherits from MyFirebaseMessagingService class,
The method takes a nonnull parameter.

solution
So the overriding method,
You need to remove the nullable question marks in onMessageReceived and onNewToken.