CodeGen from PR 17599 in Azure/azure-rest-api-specs

[Hub Generated] Review request for Microsoft.Insights to add version preview/2021-09-01-preview (#17599)

* Base from stable/2021-04-01

* Adding AMCS api version 2021-09-01-preview

* Fix Example

* Addin ID to Column definiton array

* Remove invisible character

* prettier

* R4041 - XmsIdentifierValidation

* Set Metadata as readonly

* directive for c# SDK gen rem x-ms-identifiers use

* add data collection endpoint

* fix DCE path

* remove directives for x-mx-identifiers

* apply prettier

* fix tag package on GO-track1 directives

* fix tag package on GO-track1 directives p2

* fix tag package on GO-track1 directives p3

* Update RPs api version to latest

* sort specs list

* undo api version updates of other AM RPs

* fix x-ms-identifiers

* Go - change mult-api list

* adding package-2021-05-01-preview-only

* Undo readme.go.md changes

Author: SDKAuto