Fix gateway e2e test - set timestamp in second instead of ms

[xyuanlu]

Issues

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  Fix gateway e2e test - set timestamp in second instead of ms

Description

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  This change fix a minor bug in e2e test - setting timestamp in second instead of ms.

Tests

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  NA

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Documentation (Optional)

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Commits

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Code Quality

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[xyuanlu]

This PR is ready to be merged. Approved by @zpinto

Commit message:
Fix gateway e2e test - set timestamp in second instead of ms