### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

Dynamodb Batch write request throws 500 error when DYNAMODB_ERROR_PROBABILITY is set to >0

Stack trace below
```
2023-02-01T21:50:21.918 ERROR --- [   asgi_gw_4] l.aws.handlers.logging     : exception during call chain
2023-02-01 13:50:22 Traceback (most recent call last):
2023-02-01 13:50:22   File "/opt/code/localstack/localstack/aws/chain.py", line 90, in handle
2023-02-01 13:50:22     handler(self, self.context, response)
2023-02-01 13:50:22   File "/opt/code/localstack/localstack/aws/handlers/service.py", line 122, in __call__
2023-02-01 13:50:22     handler(chain, context, response)
2023-02-01 13:50:22   File "/opt/code/localstack/localstack/aws/handlers/service.py", line 92, in __call__
2023-02-01 13:50:22     skeleton_response = self.skeleton.invoke(context)
2023-02-01 13:50:22   File "/opt/code/localstack/localstack/aws/skeleton.py", line 153, in invoke
2023-02-01 13:50:22     return self.dispatch_request(context, instance)
2023-02-01 13:50:22   File "/opt/code/localstack/localstack/aws/skeleton.py", line 165, in dispatch_request
2023-02-01 13:50:22     result = handler(context, instance) or {}
2023-02-01 13:50:22   File "/opt/code/localstack/localstack/aws/forwarder.py", line 56, in _call
2023-02-01 13:50:22     return handler(context, req)
2023-02-01 13:50:22   File "/opt/code/localstack/localstack/aws/skeleton.py", line 117, in __call__
2023-02-01 13:50:22     return self.fn(*args, **kwargs)
2023-02-01 13:50:22   File "/opt/code/localstack/localstack/aws/api/core.py", line 151, in operation_marker
2023-02-01 13:50:22     return fn(*args, **kwargs)
2023-02-01 13:50:22   File "/opt/code/localstack/localstack/services/dynamodb/provider.py", line 860, in batch_write_item
2023-02-01 13:50:22     unprocessed_items[table_name].append({key: unprocessed_items[key]})
2023-02-01 13:50:22 KeyError: 'Snapshots'
2023-02-01 13:50:22 2023-02-01T21:50:21.919  INFO --- [   asgi_gw_4] localstack.request.aws     : AWS dynamodb.BatchWriteItem => 500 (InternalError)
```

### Expected Behavior

Not throwing 500 error. only 400 (ProvisionedThroughputExceededException) is expected.

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

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

    docker run localstack/localstack
under environment set 

`DYNAMODB_ERROR_PROBABILITY=0.5`

Or with local stack cli
`DEBUG=1 DYNAMODB_ERROR_PROBABILITY=0.5 localstack start -d`

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)
through java client
dynamoDbClient.batchWriteItem(batchRequest)
I believe it's the same for any client.since it's 500 error

### Environment

```markdown
- OS:macos 13.2
- LocalStack: latest
```


### Anything else?

_No response_
handlers.modify_service_response.append(self.service, self._modify_ddblocal_arns)
        
        ROUTER.add(
            path="/shell",
            endpoint=self.handle_shell_ui_redirect,
            methods=["GET"],
        )
        ROUTER.add(
            path="/shell/<regex('.*'):req_path>",
            endpoint=self.handle_shell_ui_request,
        )
    def _modify_ddblocal_arns(self, chain, context: RequestContext, response: Response):
        """A service response handler that modifies the dynamodb backend response."""
        if response_content := response.get_data(as_text=True):
            
            content_replaced = re.sub(
                r'("TableArn"|"LatestStreamArn"|"StreamArn")\s*:\s*"arn:([a-z-]+):dynamodb:ddblocal:000000000000:([^"]+)"',
                rf'\1: "arn:\2:dynamodb:{context.region}:{context.account_id}:\3"',
                response_content,
            )
            if content_replaced != response_content:
                response.data = content_replaced
                context.service_response = (
                    None  
                )
        
        response.headers["x-amz-crc32"] = crc32(response.data) & 0xFFFFFFFF
    def _forward_request(self, context: RequestContext, region: str | None) -> ServiceResponse: