### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

APiGateway Model that being created by CDK project stores the JSON schema with a single quotes instead of double quotes which leading to an error in parsing this json object. 

you can refere to this article to see the steps 

https://dev.to/dvddpl/reduce-lambda-invocations-and-code-boilerplate-by-adding-a-json-schema-validator-to-your-api-gateway-15af

and it works fine on AWS account 

also you can look on the attached image how localstack stores the JSON object with a single quotes, I tried to edit it manually through UI but it return it back with single quotes

![Screen Shot 2022-10-18 at 4 28 08 PM](https://user-images.githubusercontent.com/106184681/196769273-0834865a-2fb3-4efc-b3a9-9da6b2ad511d.png)

### Expected Behavior

store the json schema in correct JSON format

### How are you starting LocalStack?

With the `localstack` script

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    localstack start

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

    cdklocal deploy


### Environment

```markdown
- OS:OSX
- LocalStack: 1.0.4
```


### Anything else?

_No response_
props = resource.get("Properties", {})
        role_name = props.get("Name")
        if not role_name:
            props["Name"] = generate_default_name(stack_name, resource["LogicalResourceId"])
        content_type = props.get("contentType")
        if not content_type:
            props["contentType"] = "application/json"
    @staticmethod
    def get_deploy_templates():
        def _handle_result(result: dict, logical_resource_id: str, resource: dict):
            resource["PhysicalResourceId"] = result["id"]
        return {
            "create": {
                "function": "create_model",
                "parameters": {
                    "name": "Name",
                    "restApiId": "RestApiId",
                    "schema": "Schema",
                    "contentType": "ContentType",
                },
                "types": {"schema": str},
                "result_handler": _handle_result,
            }
        }
class GatewayAccount(GenericBaseModel):