fix: Set requestTimeEpoch with ms precision (#8020)

[HaaLeo]

Which issue(s) does this change fix?

Fixes #8020

Why is this change necessary?

It's necessary to comply with the APIGateway context specification

How does it address the issue?

set the timestamp with ms resolution

What side effects does this change have?

N/A

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• [x] Add input/output type hints to new functions/methods
• [x] Write design document if needed (Do I need to write a design document?)
• [x] Write/update unit tests
• [x] Write/update integration tests
• [x] Write/update functional tests if needed
• [x] make pr passes
• [x] make update-reproducible-reqs if dependencies were changed
• [x] Write documentation

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

[HaaLeo]

@roger-zhangg can we give this PR another try? I've updated it and it should be all good. However, the test coverage seems to fail on my local machine.

[vicheey]

Updated branch and retry the test

[HaaLeo]

@vicheey since the tests passed. Can we merge this?