CodeGen from PR 16426 in Azure/azure-rest-api-specs

publish Microsoft.AVS 2021-12-01 API (#16426)

* copy 2021-06-01 API

* replace "2021-06-01" with "2021-12-01"

* add 2021-12-01 changes

* update readme

* add go

* add java

* fix go

Author: SDKAuto