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# Type of request: This is a ...

[x ] bug report
[ ] feature request

# Detailed description

Not able to use the edge service to write metric data to cloudwatch via the javascript aws-sdk.

However, It **DOES** work when using the deprecated cloudwatch port.

## Expected behavior

Metric data to be visible when calling `awslocal cloudwatch list-metrics`

## Actual behavior

404 from edge service. No metric data is persisted, localstack instance logs the following info:

```
INFO:localstack.services.edge: Unable to determine forwarding port for API "monitoring" - please make sure this API is enabled via the SERVICES configuration
```

# Steps to reproduce

Run JS code in "Client code" section.
See 404 Error

## Command used to start LocalStack

`TMPDIR=/tmp/localstack docker-compose up`

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

```js
const AWS = require('aws-sdk')
const cw = new AWS.CloudWatch({
  endpoint: 'http://localhost:4566',
})

const data = {
  Namespace: 'ns',
  MetricData: [
    {
      MetricName: 'metric-name',
      Timestamp: new Date(),
      Value: 12345,
      Unit: 'Milliseconds',
      Dimensions: [
        { Name: 'Environment', Value: 'local' },
      ]
    }
  ]
}

cw.putMetricData(data, (err, data) => {
  if (err) {
      console.log('Error', err)
  } else {
      console.log('Success', JSON.stringify(data))
  }
})
```

asynchronous=not config.SYNCHRONOUS_API_GATEWAY_EVENTS)
    except Exception as e:
        LOG.warning('Unable to run Lambda function on API Gateway message: %s %s' % (e, traceback.format_exc()))
def process_sns_notification(func_arn, topic_arn, subscription_arn, message,
        message_attributes, unsubscribe_url, subject='',):
    event = {
        'Records': [{
            'EventSource': 'localstack:sns',
            'EventVersion': '1.0',
            'EventSubscriptionArn': subscription_arn,
            'Sns': {
                'Type': 'Notification',
                'MessageId': str(uuid.uuid4()),
                'TopicArn': topic_arn,
                'Subject': subject,
                'Message': message,
                'Timestamp': timestamp_millis(),
                'SignatureVersion': '1',
                
                
                'Signature': 'EXAMPLEpH+..',
                'SigningCertUrl': 'https://sns.us-east-1.amazonaws.com/SimpleNotificationService-000000000.pem',
                'UnsubscribeUrl': unsubscribe_url,
                'MessageAttributes': message_attributes
            }
        }]
    }
    return run_lambda(event=event, context={}, func_arn=func_arn, asynchronous=not config.SYNCHRONOUS_SNS_EVENTS)
def process_kinesis_records(records, stream_name):
    def chunks(lst, n):