### Is there an existing issue for this?

- [X] I have searched the existing issues

### Feature description

Basically we want to only run the lambda when an insert is occurring in DynamoDB.
I tested using Dynobase deleting a record and the lambda still triggered.

```
resource "aws_lambda_event_source_mapping" "event-log" {
	event_source_arn  = aws_dynamodb_table.event-log.stream_arn
	function_name     = module.main.lambda-arn
	starting_position = "LATEST"
	enabled = true # change to false when truncating the table in localstack
	maximum_retry_attempts = 1 # limit retry on failure to 1 for now

	# https://dev.to/aws-builders/filtering-dynamodb-streams-before-lambda-p5p
	filter_criteria { # Doesn't seem to work on LocalStack for now
		filter {
			pattern = jsonencode({
				body = {
					eventName : ["INSERT"]
				}
			})
		}
	}
}
```


### 🧑‍💻 Implementation

_No response_

### Anything else?

 https://dev.to/aws-builders/filtering-dynamodb-streams-before-lambda-p5p
return method == "POST" and bool(re.match(PATH_REGEX_TEST_INVOKE_API, path))
def get_stage_variables(context: ApiInvocationContext) -> Optional[Dict[str, str]]:
    if is_test_invoke_method(context.method, context.path):
        return None
    if not context.stage:
        return {}
    region_name = get_api_region(context.api_id)
    api_gateway_client = aws_stack.connect_to_service("apigateway", region_name=region_name)
    try:
        response = api_gateway_client.get_stage(restApiId=context.api_id, stageName=context.stage)
        return response.get("variables")
    except Exception:
        LOG.info("Failed to get stage %s for API id %s", context.stage, context.api_id)
        return {}
def gateway_response_to_response_json(item, api_id):
    base_path = "/restapis/%s/gatewayresponses" % api_id
    item["_links"] = {
        "self": {"href": "%s/%s" % (base_path, item["responseType"])},
        "gatewayresponse:put": {
            "href": "%s/{response_type}" % base_path,
            "templated": True,
        },
        "gatewayresponse:update": {"href": "%s/%s" % (base_path, item["responseType"])},
    }
    item["responseParameters"] = item.get("responseParameters", {})
    item["responseTemplates"] = item.get("responseTemplates", {})
    return item
def get_gateway_responses(api_id):