Panic occurs when generating OAuth2 token with an invalid refresh token value

[Nuvindu]

Description:
When a gmail:Client is initialized with an invalid refresh token, a panic occurs instead of mapping the error value to the variable. That happens when oauth2 module tries to generate a token using that invalid refresh token value

Steps to reproduce:

1. Create new Ballerina project
2. Modify the main.bal file as below and run the project

import ballerinax/googleapis.gmail;

configurable string clientId = "client-id";
configurable string clientSecret = "client-secret";
configurable string refreshToken = "refresh-token";

public function main() {
    gmail:Client|error gmail = new ({
        auth: {
            clientId,
            clientSecret,
            refreshToken
        }
    });
}

[MohamedSabthar]

Hi @Nuvindu, This is not a bug but a design choice. We already have an issue for this: #3494

[github-actions]

This issue is NOT closed with a proper Reason/ label. Make sure to add proper reason label before closing. Please add or leave a comment with the proper reason label now.

      - Reason/EngineeringMistake - The issue occurred due to a mistake made in the past.
      - Reason/Regression - The issue has introduced a regression.
      - Reason/MultipleComponentInteraction - Issue occured due to interactions in multiple components.
      - Reason/Complex - Issue occurred due to complex scenario.
      - Reason/Invalid - Issue is invalid.
      - Reason/Other - None of the above cases.