Remove the warning messages for MSGraph migration

[BethanyZhou]

Description

Remove the warning messages for MSGraph migration from Az.KeyVaut, Az.Resources, Az.Sql, Az.Aks

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate ChangeLog.md file(s) has been updated:
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
  • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header -- no new version header should be added
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • a cmdlet design review was approved for the changes in this repository (Microsoft internal only)
    • {Please put the link here}
  • the markdown help files have been regenerated using the commands listed here

[isra-fel]

Otherwise it LGTM

[BethanyZhou]

Resolved. Did I miss any other modules in your mind? @isra-fel I just did a text search.

[isra-fel]

StorageSync and Synapse also migrated to MSGraph. But they did add the warning message, so there's nothing more to do.