Azure bot app authentication

[QianYang0]

Ran into 401 authentication issue when using Teams SDK to build the bot.

Context:
Teams SDK: version 2.0.5
Language: c#
Azure bot: user assigned managed identity type, deployed through app service

Issues:
token.BotFramework.come/api/userToken is always triggered no matter OAuth is configured or not. 401 returned.
This code fixed the issue: https://github.com/OfficeDev/microsoft-365-agents-toolkit/blob/b3312c4a2f02ac376a1645faf696c80c39f67851/templates/vs/csharp/default-bot/Program.cs.tpl#L14-L27

C# app authentication documentation should be updated with this code for guidance.

[singhk97]

Hey, we have guidance for how to setup the user assigned managed identity here. Did you try this setup?