Fix bug of CAE new request disposing

[msJinLei]

Request are used after disposed in AuthenticationHelper and so the previous request cannot be disposed.
The new request should be disposed finally.

• Normal case: smoke test coverred https://dev.azure.com/azure-sdk/internal/_build/results?buildId=1385063&view=results
• 401 case: manual tests covered

Description

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]

LGTM. Have you tested CAE scenario?

[dolauli]

I double check the code and think we need to dispose the old response here.

The base branch was changed.

[isra-fel]

LGTM

[VeryEarly]

Suggested change

	using (var newRequest = await request.CloneWithContent(request.RequestUri, request.Method))
	using (var newRequest = await request.CloneWithContent(request.RequestUri, request.Method))
	using (var response = await next(request, cancelToken, cancelAction, signal))

[msJinLei]

Refer to the implementation of pipeline, the original request and response will be disposed finally.