Error codes are not helping, please improve error logs

[ffyhlkain]

Describe the bug
We're trying to get this plugin running, but we're stuck in the authorization process and the error messages are not helping to find out what the problem is. Like many other users report here, the log output is not helping to find out what the problem is. While I recognize that this might not always be easy, the current error message is not even pointing towards a direction what fails and what to double check.

To Reproduce
No need to reproduce: check the code and improve the error log output.

Example:
2024/10/24 09:28:52.267 14336 14388 Warn Unity *** [Play Games Plugin 0.11.01] 10/24/24 9:28:52 +02:00 ERROR: Returning an error code.

Expected behavior
A clear message comes out in the log, indication what the problem is or pointing towards it.

Example:
2024/10/24 09:28:52.267 14336 14388 Warn Unity *** [Play Games Plugin 0.11.01] 10/24/24 9:28:52 +02:00 ERROR: Returning an error code: 12 (OAuth server denies authorization. Have you added the correct SHA1 key?)

Observed behavior
A meaningless error message is printed:

2024/10/24 09:28:52.267 14336 14388 Warn Unity *** [Play Games Plugin 0.11.01] 10/24/24 9:28:52 +02:00 ERROR: Returning an error code.
2024/10/24 09:28:52.267 14336 14388 Warn Unity UnityEngine.DebugLogHandler:Internal_Log(LogType, LogOption, String, Object)
2024/10/24 09:28:52.267 14336 14388 Warn Unity UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
2024/10/24 09:28:52.267 14336 14388 Warn Unity UnityEngine.Logger:Log(LogType, Object)
2024/10/24 09:28:52.267 14336 14388 Warn Unity GooglePlayGames.OurUtils.PlayGamesHelperObject:Update()

In this case, there's no direction where or what to double check, leaving the developer in the unknown.

Versions

• Unity version: 6000.0.14
• Google Play Games Plugin for Unity version: 0.11.01

Additional context
When researching the auth in problem, you'll find many reports by devs indicating that the logging doesn't help finding the errors, but rather everyone is guessing what the problem might be, doing the whole process from the scratch only to hope that it might help.

E.g.
https://discussions.unity.com/t/google-play-games-canceled/938672/7