Fix Messaging doc (#97)

Author: paulb777

Firebase/Messaging/FIRMessaging.m

@@ -227,7 +227,7 @@ - (void)setupNotificationListeners {
                object:nil];
   [center addObserver:self
              selector:@selector(defaultInstanceIDTokenWasRefreshed:)
-                 name:kFIRMessagingInstanceIDTokenRefreshNotification
+                 name:kFIRMessagingRegistrationTokenRefreshNotification
                object:nil];
   [center addObserver:self
              selector:@selector(didReceiveAPNSToken:)

Firebase/Messaging/FIRMessagingConstants.h

@@ -51,7 +51,8 @@ FOUNDATION_EXPORT NSString *const kFIRMessagingApplicationSupportSubDirectory;
 // Notifications
 FOUNDATION_EXPORT NSString *const kFIRMessagingAPNSTokenNotification;
 FOUNDATION_EXPORT NSString *const kFIRMessagingFCMTokenNotification;
-FOUNDATION_EXPORT NSString *const kFIRMessagingInstanceIDTokenRefreshNotification;
+FOUNDATION_EXPORT NSString *const kFIRMessagingInstanceIDTokenRefreshNotification __deprecated_msg("Use kFIRMessagingRegistrationTokenRefreshNotification instead");
+FOUNDATION_EXPORT NSString *const kFIRMessagingRegistrationTokenRefreshNotification;
 
 FOUNDATION_EXPORT const int kFIRMessagingSendTtlDefault; // 24 hours
 

Firebase/Messaging/FIRMessagingConstants.m

@@ -47,5 +47,7 @@
 NSString *const kFIRMessagingFCMTokenNotification = @"com.firebase.iid.notif.fcm-token";
 NSString *const kFIRMessagingInstanceIDTokenRefreshNotification =
     @"com.firebase.iid.notif.refresh-token";
+NSString *const kFIRMessagingRegistrationTokenRefreshNotification =
+    @"com.firebase.iid.notif.refresh-token";
 
 const int kFIRMessagingSendTtlDefault = 24 * 60 * 60; // 24 hours