chore: Add region skip condition and retry for http test

[qingchm]

Issue #, if available:
N.A.

Description of changes:
To exclude regions for http tests so it does not get tested in regions not supporting http api

Description of how you validated changes:
This change uses the same decorator used in other http api tests

Checklist:

• Add/update unit tests using:
  • Correct values
  • Bad/wrong values (None, empty, wrong type, length, etc.)
  • Intrinsic Functions
• Add/update integration tests
• make pr passes
• Update documentation
• Verify transformed template deploys and application functions as expected
• Do these changes include any template validations?
  • Did the newly validated properties support intrinsics prior to adding the validations? (If unsure, please review Intrinsic Functions before proceeding).
    • Does the pull request ensure that intrinsics remain functional with the new validations?

Examples?

Please reach out in the comments, if you want to add an example. Examples will be
added to sam init through https://github.com/awslabs/aws-sam-cli-app-templates/

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[sriram-mv]

Could there be issues surrounding the fact that the stacks were not cleaned up correctly, is that a possibility here?

[qingchm]

Nope for each stack the stack name is generated with a unique hash, random.choice(string.ascii_lowercase) for i in range(RANDOM_SUFFIX_LENGTH), so a failed clean up will never affect stack creation