[ECS/Service Connect] [request]: Control network traffic between ECS Services

### Community Note

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**Tell us about your request**
What do you want us to build?
When using Service Connect, I would like to be able to control network flow between services (similar to Security Groups) on the task level. As an analogy, the request is to have the equivalent of [Kubernetes Network Policies](ork-policies/).

**Which service(s) is this request for?**
ECS / Service Connect

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
Service Authorization mechanism for services in ECS with Service Connect enabled.

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

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

**Attachments**
If you think you might have additional information that you'd like to include via an attachment, please do - we'll take a look. (Remember to remove any personally-identifiable information.)

The request concerns ECS/Service Connect and compares the desired behavior with Kubernetes Network Policies. No repository file, test, or entry point is identified, so start by understanding the existing Service Connect authorization and task-level networking model. Done would require an agreed feature design plus implementation and test scope.

Written by the indexing model from the issue text.