CodeGen from PR 20272 in Azure/azure-rest-api-specs

Add 2022-08-01-preview version to Microsoft.SignalRService/SignalR (#20272)

* Adds base for updating Microsoft.SignalRService from version stable/2022-02-01 to version 2022-08-01-preview

* Update readme.md

* Update swagger and examples

* Updates

* revert adding 200 response code to put custom domain

Author: SDKAuto