### 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_
from localstack.services.iam import iam_listener, iam_starter
    return Service("iam", listener=iam_listener.UPDATE_IAM, start=iam_starter.start_iam)
@aws_provider()
def sts():
    from localstack.services.sts import sts_listener, sts_starter
    return Service("sts", start=sts_starter.start_sts, listener=sts_listener.UPDATE_STS)
@aws_provider()
def kinesis():
    from localstack.services.kinesis import kinesis_listener, kinesis_starter
    return Service(
        "kinesis",
        listener=kinesis_listener.UPDATE_KINESIS,
        start=kinesis_starter.start_kinesis,
        check=kinesis_starter.check_kinesis,
    )
@aws_provider()
def kms():
    from localstack.services.kms import kms_listener, kms_starter
    return Service("kms", listener=kms_listener.UPDATE_KMS, start=kms_starter.start_kms)
@aws_provider(api="lambda")
def awslambda():
    from localstack.services.awslambda import lambda_starter
    return Service(
        "lambda",
        start=lambda_starter.start_lambda,
        stop=lambda_starter.stop_lambda,
        check=lambda_starter.check_lambda,
    )
@aws_provider()
def logs():