Fix for domain join error if domain join user account is already in A…

…dministrators group (#728)

* Automated update for ARM templates

* Check if the domain join user is already an Administrators member
Fix typo in variable name

* Parse AdminUserName to perform successful check

* Parse AdminUserName to perform successful check

* Correct parsing of username to check for Administrators membership

* Add troubleshooting output

* Fix concatenation and trimming of CheckAdminUserName

* Fix capitalization

* Remove "self-referencing" DSCStorageScripts.zip

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Co-authored-by: SvenAelterman <[email protected]>