[Unity Game Engine Plugin] Faulty Client ID validity check

[Marenthyu]

Brief description
In its currently available public Build, the Unity Game Engine Plugin does a check against the oauth2/token Endpoint, trying to create a client_credentials Token. Due to this, the UI for the SDK will consistently claim that any entered Client ID is "invalid".

How to reproduce

1. Import the Unity SDK as described in the Docs
2. Insert a Client ID (or any value)
3. Observe the "Please enter a valid ClientId!" Status

Expected behavior
Valid Client IDs are shown as valid.

Replacing the call to /token with /device and removing the unused query Parameters should be a sufficient replacement as a "quick-fix".

Screenshots

Additional context or questions
Thank you @hasenknopf and @Lyretto for bringing this issue to our attention!