Update the csharp codegen settings for mysql - #38566

Errors occurred while generating SDK from specification/mysql. Follow the steps at https://aka.ms/azsdk/sdk-automation-faq#how-to-view-the-detailed-sdk-generation-errors to view detailed errors.
[ERROR] Failed to build the sdk project: {package-name} for service: mysql. Exit code: False. Please review the detail errors for potential fixes. If the issue persists, contact the DotNet language support channel at https://aka.ms/azsdk/dotnet-teams-channel and include this spec pull request.
The generation process failed for specification-mysql-resource-manager-Microsoft.DBforMySQL-FlexibleServers-tspconfig.yaml. Refer to the full log for details.