[ECS] [request]: Pin before install hook lambda function

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**Tell us about your request**
What do you want us to build?
As a ECS User, I want to be able to have a default before/after install hook for my ECS service update, to avoid wrong hook to be selected. This should be a very low hanging fruit and it will provide tremendous value to the customers. Please show customer obsession and prioritize this please.

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

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
What outcome are you trying to achieve, ultimately, and why is it hard/impossible to do right now? What is the impact of not having this problem solved? The more details you can provide, the better we'll be able to understand and solve the problem.

Basically we have a django service that we are running as our web backend, and we have a migration lambda that we run as pre install hook everytime we deploy it, selecting the wrong hook here can results in deployment failure and temporary outage.

**Are you currently working around this issue?**
How are you currently solving this problem?
Manual selection works, but it's very error prone at scale.

**Additional context**
Anything else we should know?
Please please please provide this.

**Attachments**
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