workflow.md - AWS API update broke commands, added new flags.

It looks like AWS updated APIs and by this introduced breaking changes. Potentially, any API that accepts payloads could have the same issue. Now it “thinks” that the provided payload base64 encoded.

Luckily AWS CLI version 2 has --cli-binary-format a flag that allows you to specify how the binary input parameters interpreted. Option: raw-in-base64-out.