### 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
content = json.loads(content)
        except Exception:
            pass
        return content
    raise ClientError("Unexpected value for LAMBDA_FALLBACK_URL: %s" % config.LAMBDA_FALLBACK_URL)
def get_lambda_policy(function, qualifier=None):
    iam_client = aws_stack.connect_to_service("iam")
    policies = iam_client.list_policies(Scope="Local", MaxItems=500)["Policies"]
    docs = []
    for p in policies:
        
        versions = iam_client.list_policy_versions(PolicyArn=p["Arn"])["Versions"]
        default_version = [v for v in versions if v.get("IsDefaultVersion")]
        versions = default_version or versions
        doc = versions[0]["Document"]
        doc = doc if isinstance(doc, dict) else json.loads(doc)
        if not isinstance(doc["Statement"], list):
            doc["Statement"] = [doc["Statement"]]
        for stmt in doc["Statement"]:
            stmt["Principal"] = stmt.get("Principal") or {"AWS": get_aws_account_id()}
        doc["PolicyArn"] = p["Arn"]
        doc["PolicyName"] = p["PolicyName"]
        doc["Id"] = "default"
        docs.append(doc)
    
    policy_name = get_lambda_policy_name(
        aws_stack.lambda_function_name(function), qualifier=qualifier
    )