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# Type of request: This is a ...

[x] bug report
[ ] feature request

# Detailed description
When I call the Lambda PutFunctionEventInvokeConfig API using the aws-java-sdk, the sdk throws an exception claiming it cannot parse the LastModified timestamp in the response:
```
software.amazon.awssdk.core.exception.SdkClientException: Unable to parse date : 2021-05-28T16:02:30.018Z
        at software.amazon.awssdk.core.exception.SdkClientException$BuilderImpl.build(SdkClientException.java:98)
        at software.amazon.awssdk.protocols.core.StringToInstant.lambda$safeParseDate$0(StringToInstant.java:77)
        at software.amazon.awssdk.protocols.core.StringToInstant.convert(StringToInstant.java:54)
        at software.amazon.awssdk.protocols.core.StringToInstant.convert(StringToInstant.java:32)
```

For comparison, the response for a getting a FunctionEventInvokeConfig for a Lambda of a real AWS account using the aws-cli is the following:
```
{
    "LastModified": "2021-05-27T19:26:43.454000-07:00",
    "FunctionArn": "...",
    ...
}
```

## Expected behavior
LambdaAsyncClient in aws-java-sdk should correctly parse the response for a PutFunctionEventInvokeConfig request.

## Actual behavior
LambdaAsyncClient in aws-java-sdk throws an exception when parsing the LastModified field in the response.

# Steps to reproduce

## Command used to start LocalStack
```
docker run -d --rm --name localstack -p 4566:4566 localstack/localstack:latest
```

## Client code (AWS SDK code snippet, or sequence of "awslocal" commands)
```
val putEventInvokeConfigRequest =
  PutFunctionEventInvokeConfigRequest.builder
    .functionName(functionName)
    .maximumEventAgeInSeconds(21600)
    .maximumRetryAttempts(0)
    .build
lambdaClient.putFunctionEventInvokeConfig(putEventInvokeConfigRequest)
```


)
                            messages = result.get('Messages')
                            if not messages:
                                continue
                        LOG.debug('Sending event from event source %s to Lambda %s' % (queue_arn, lambda_arn))
                        res = send_event_to_lambda(queue_arn, queue_url, lambda_arn, messages, region=region_name)
                        if not res:
                            unprocessed_messages[queue_arn] = messages
                    except Exception as e:
                        LOG.debug('Unable to poll SQS messages for queue %s: %s' % (queue_arn, e))
            except Exception:
                pass
            finally:
                time.sleep(SQS_POLL_INTERVAL_SEC)
    LOG.debug('Starting SQS message polling thread for Lambda API')
    SQS_LISTENER_THREAD['_thread_'] = FuncThread(listener_loop)
    SQS_LISTENER_THREAD['_thread_'].start()
def process_sqs_message(queue_name, region_name=None):
    
    try:
        region_name = region_name or aws_stack.get_region()
        queue_arn = aws_stack.sqs_queue_arn(queue_name, region_name=region_name)
        sources = get_event_sources(source_arn=queue_arn)
        arns = [s.get('FunctionArn') for s in sources]
        source = (sources or [None])[0]
        if not source:
            return False
        LOG.debug('Found %s source mappings for event from SQS queue %s: %s' % (len(arns), queue_arn, arns))
        start_lambda_sqs_listener()
        return True