fix(transform): AWS DynamoDB Send Payload

[jshlbrd]

Description

• Fixes the sendAWSDynamoDB transform payload

Motivation and Context

The transform sends the message data, but has broken support for sending a JSON value from the message. This removes the broken support and makes it so this has same behavior as every other send transform (sends message data only).

How Has This Been Tested?

This was caught during an E2E example test.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.