Fix: sam sync defintion validator handling file opened event

[hawflau]

Which issue(s) does this change fix?

N/A

Why is this change necessary?

For definition files (e.g. APIGW, SFN), a validation step is done for each FS event caught by watchdog. The validation step compares the file changes and determines if it's a valid change to sync. However, the validation step checks the file as of current but not the time when the event happened. As a result, we saw "changes" occurred and validated for a "File Opened Event", which is then ignored, and thus did not result in any sync.

How does it address the issue?

Explicitly skip File Opened Event in the validation step.

What side effects does this change have?

Definition files are not validated for a File Opened Event. However, this should be fine since we do not create sync flow from File Opened Event anyway.

Mandatory Checklist

PRs will only be reviewed after checklist is complete

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

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