PushNotifications.fromJson fails without devices

[konrad-xtention]

Checklist

• I could not find a solution in the documentation, the existing issues or discussions.
• I already asked for help in the chat

In which Project did the bug appear?

Other

If you selected "Other" as Project, please enter in which project the bug occurred.

No response

On which platform did the bug appear?

Android

SDK Version

0.37.0

Describe the problem caused by this bug

In 0.37.0, all fields of PushNotification were made optional. But despite this change, PushNotifications.fromJson fails when no devices are present.

It should be possible to use fromJson on Json from toJson, but this throws an exception:

final PushNotification notification = PushNotification.fromJson(PushNotification().toJson());

Steps To Reproduce

Minimal reproduction:

final PushNotification notification = PushNotification.fromJson({});

Expected result: Get a PushNotification with all fields set to null.
Actual result: An exception is thrown.

Screenshots or Logs

type 'Null' is not a subtype of type 'String' in type cast

Security related

No response