fix(messaging, ios): badge is in the message, not the notification

[russellwheatley]

Description

Print out the message in Xcode. You can see the badge is in the message, not the alert dictionary.

To test, I sent a message with a badge:

admin
.messaging()
.sendToDevice(
  [iosToken],
  {
    data: {
      something:'else',
    },
    notification: {
      title: 'A great title',
      body: 'Great content',
      badge: '3'
    },
  },
  {
    // Required for background/terminated app state messages on iOS
    contentAvailable: true,
    // Required for background/terminated app state messages on Android
    priority: 'high',
  }
)

Print out print('${message.notification?.apple?.toMap()}'); on the incoming message from onMessage. You can see the badge is now correctly on the AppleNotification instance.

{badge: 3, subtitle: null, subtitleLocArgs: [], subtitleLocKey: null, imageUrl: null, sound: null}

I also had to convert the int type to a string in the underlying implementation as badge is a String? type and the encoding silently fails if I don't. See implementation

Related Issues

closes #9533

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