[ECS] [Feature Request]: RAM shared SSM Parameter Store support in task definitions

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**Tell us about your request**
Systems Manager Parameter shared via RAM is Currently not Supported as a Secret value in ECS.

**Which service(s) is this request for?**
ECS, Fargate

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
We have many AWS accounts running ECS Fargate and we have a single parameter that stores a license key, that license is shared and we don't want to maintain it in every single AWS account (i.e. if we need to update the license).

It would be awesome if we could store the value in a single "shared services" account so that it could be loaded by any ECS Fargate task in our AWS organization.

**Are you currently working around this issue?**
We are duplicating the parameter in every single AWS account.

**Additional context**
N/A

**Attachments**
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