### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When attempting to sign some document using Localstack KMS inside a lambda container (also running on localstack), the localstack KMS listener returns some unknown error.

The KMS key and lambda containers have been created from the same CDK app deploy, and I can see all the resources in the localstack web console.

The test application I'm using to prove this behaviour is available here:
https://github.com/LukaHedt/localstack_kms_test

Instructions to run are in the main Readme, and the `/localstack/Readme.md` file.

`aws-sdk` returns an unknown error, and the localstack docker logs that I receive are available here:
https://pastebin.com/58Z3fXi3

Have done an amount of testing and can confidently claim the following:
- Have tested on multiple machines with the same outcome
- Doesn’t make a difference if I specify an ARN or a KeyID in the signing request
- Downgrading localstack versions either didn’t make a difference, or I couldn’t actually deploy a localstack container with version 0.12.20 or lower.

### Expected Behavior

KMS Sign should return a signature for the given payload.

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

Test application demonstrating the current behaviour is available here:

https://github.com/LukaHedt/localstack_kms_test

Full instructions to run are in the `/localstack/Readme.md` file.


### Environment

```markdown
- OS: MacOS Monteray 12.3
- LocalStack: 0.14.0
```


### Anything else?

_No response_
table_props["Replicas"] = replicas = table_props.get("Replicas") or []
                for repl_update in data["ReplicaUpdates"]:
                    for key, details in repl_update.items():
                        region = details.get("RegionName")
                        if key == "Create":
                            details["ReplicaStatus"] = details.get("ReplicaStatus") or "ACTIVE"
                            replicas.append(details)
                        if key == "Update":
                            replica = [r for r in replicas if r.get("RegionName") == region]
                            if replica:
                                replica[0].update(details)
                        if key == "Delete":
                            table_props["Replicas"] = [
                                r for r in replicas if r.get("RegionName") != region
                            ]
                
                schema = SchemaExtractor.get_table_schema(table_name)
                result = {"TableDescription": schema["Table"]}
                update_response_content(response, json_safe(result), 200)
            return
        elif action == "DescribeTable":
            table_name = data.get("TableName")
            table_props = DynamoDBRegion.get().table_properties.get(table_name)
            if table_props:
                content = json.loads(to_str(response.content))
                content.get("Table", {}).update(table_props)
                update_response_content(response, content)
            
            table_definitions = DynamoDBRegion.get().table_definitions.get(table_name)
            if table_definitions: