Az.CognitiveServices - Update SDK to 7.0, Improve error message

[yangyuan]

Description

Update SDK to 7.0
Improve error message when server responses empty body

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)
  • the markdown help files have been regenerated using the commands listed here

[VeryEarly]

Hi @yangyuan ,

Your PR looks good to me, could you please format your code in this convention?
Just to improve the readability.

this.CognitiveServicesClient.Accounts.Update(this.ResourceGroupName,
this.Name,
new CognitiveServicesAccount()
{
Properties = properties
});

[yangyuan]

@markcowl update the format as suggested :)

[VeryEarly]

/azp run

[azure-pipelines]

Pull request contains merge conflicts.

[VeryEarly]

@markcowl update the format as suggested :)

Hi @yangyuan ,

github display my suggested format change in a different way :(

sent you the right one through teams, also please fix the conflicting files