restXml and restJson1 should support the httpChecksum trait

[frij-aws]

Background

• What do these changes do?
  Add the @httpChecksum trait to the list of supported traits for restXml and restJson1

• Why are they important?
  Codegens need to know which traits to ignore and which to honor. They do this based on the traits listed in the protocol definition. If codegens ignore the @httpChecksum trait, they will generate incorrect S3 code (for example)

Testing

• How did you test these changes?
  Tested restXml with the ABAP SDK, with a preview build of S3 and ran the integration and smoke tests (failed before the change, passed after). Did not test for restJson1.

Links

• Based on internal discussions

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[github-actions]

This pull request does not contain a staged changelog entry. To create one, use the ./.changes/new-change command. For example:

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