aws-applicationautoscaling: Missing treatmissingdata attribute in `BasicStepScalingPolicyProps`

[EHadoux]

Describe the bug

When defining a step scaling policy for a fargate service, the BasicStepScalingPolicyProps doesn't allow for the specification of how to treat the missing data for the alarms that are created. I imagine that it's because it's potentially creating several alarms and we don't want them having the same behaviour. But I couldn't find a way to find the alarms created to then add that afterwards. I'm scaling up and down depending on the ApproximateNumberOfMessagesVisible in an SQS, but the metric doesn't return a datapoint when it's empty (instead of 0).

Expected Behavior

We have a way to specify how the alarms treat the missing data.

Current Behavior

The attribute doesn't exist and we can't get the alarms created with scaleOnMetric. The default on the alarms is to treat the missing data as missing.

Reproduction Steps

1. Create a fargate service
2. call autoScaleTaskCount
3. call scaleOnMetric

Possible Solution

No response

Additional Information/Context

No response

CDK CLI Version

2.37.1

Framework Version

No response

Node.js Version

16.15.1

OS

Mac OS

Language

Typescript

Language Version

Typescript (4.7.4)

Other information

No response