Update to new update management solution and remove region dependency for LA

Current issue:
The Update management solution are not part of each Azure region, meaning that your deployment for log analytics and the automation account with update management will need to reside in supported regions due to linkage between Automation Account and Log analytics. (Example, Azure Automation account cannot be linked to Log analytics that resides in Sweden Central). In addition, this also effects Change tracking and Inventory solutions.
This gives several drawbacks as you do not have a self-contained Landing Zone in one Azure region and you will need to send logs to a separate region or have multiple log analytics.

Proposed solution
When GA, move to Update Center solution (public preview as of this date) as this removes dependency of the linkage between automation account and log analytics.

Review the Azure Landing Zones documentation covering Update management, Change tracking, and Inventory, then verify whether Update Center has reached GA. Compare the current Automation Account and Log Analytics linkage guidance with the Update Center approach. Done means the documentation describes the new solution without requiring the region-dependent linkage.

Written by the indexing model from the issue text.