Cloudwatch: Update AWS DynamoDB Metrics

[LeonardoBoleli]

What is this feature?

[Add a brief description of what the feature or update does.]

Why do we need this feature?

[Add a description of the problem the feature is trying to solve.]

Who is this feature for?

[Add information on what kind of user the feature is for.]

Which issue(s) does this PR fix?:

Fixes #

Special notes for your reviewer:

Please check that:

• It works as expected from a user's perspective.
• If this is a pre-GA feature, it is behind a feature toggle.
• The docs are updated, and if this is a notable improvement, it's added to our What's New doc.

[njvrzm]

One small change request.

[njvrzm]

Hi @LeonardoBoleli, and thanks for your contribution! I've requested one minor change. Also if you could add a little bit of information to the pull request for the record that would be great.

[iwysiu]

Thanks for pr!

link to aws docs:

• for the events metrics
• for dynamodb metrics

[njvrzm]

👍🏻