Read push notification
Reads the Google service account that the service uses to send push notifications. The response contains the saved JSON key with its private key in clear text. `serviceAccountCredential` is `null` when you have not configured push notifications.
Configure push notification
Saves the Google service account that the service uses to send Firebase Cloud Messaging push notifications to the devices of your individuals (the `pushNotificationToken` and `deviceType` of an individual), for example when you issue a credential to an individual or send a verification request to it. Send the JSON key of the service account as it is. The service checks the key and makes no network call. It replaces a saved service account, so this operation and Update push notification do the same.
Update push notification
Replaces the Google service account that the service uses to send Firebase Cloud Messaging push notifications. It does the same as Configure push notification: send the full JSON key of the new service account.