[ECS] [Feature Request]: Scale-out action resets scale-in cooldown triggering scale-in action

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**Tell us about your request**

Currently, when an ECS Auto Scaling group scales out, it resets the cooldown of the scale-in process for that group. This behavior can lead to unintended consequences when there are multiple scaling policies based on different metrics. For example, when a scale-out policy with a shorter cooldown than the scale-in cooldown is triggered, it can immediately lead to a scale-in action by another policy, creating a loop of scaling actions.

**Which service(s) is this request for?**
This could be ECS

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**

A TargetScaling policy based on CPU_AVERAGE that scales both in and out.
A StepScaling policy based on a CloudWatchMetric for GetRecords.IteratorAgeMilliseconds of a Kinesis stream that only scales out.

If the first policy triggers a scale-out action, it resets the scale-in cooldown, and if the second policy meets its criteria for scale-in at that moment, it will immediately trigger a scale-in action. This loop can repeat indefinitely if the scale-out policy has a shorter cooldown than the scale-in cooldown.

**Are you currently working around this issue?**
How are you currently solving this problem?

To mitigate this behaviour, we have increased the scale-out cooldown of the StepScaling policy from 1min to 15mins to decrease the frequency which this occurs - as far as I am aware there is no fix for this issue.

**Additional context**
Anything else we should know?

We request a feature enhancement that allows the scale-out process to reset the cooldown of scale-in for its Auto Scaling group without triggering any scaling policies that meet the criteria for a scale-in action. This enhancement would help prevent unintended scaling loops in scenarios where multiple scaling policies are in use, each based on different metrics.

**Attachments**
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Start by reviewing the ECS Auto Scaling behavior described for TargetScaling and StepScaling policies, focusing on how scale-out and scale-in cooldowns interact. Reproduce the scenario using CPU_AVERAGE, GetRecords.IteratorAgeMilliseconds, and the stated cooldowns; done means the requested cooldown handling prevents the unintended scaling loop without suppressing valid scaling actions.

Written by the indexing model from the issue text.