[Fargate] [request]: Increase Container definition size limit

**Tell us about your request**
Increase the container definition size limit from 32kb to 64kb

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

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
Currently we use the `secrets` argument in the container definition in conjunction with SSM params, but one of our projects is reaching the container definition limit of 32kb.

Moving it over to use something like S3 and KMS is not feasible for us now and will require deviating from standard functionality supplied by ECS fargate, and most properly have to redo our whole secrets approach, which is not something we feel like repeating again.

This impacts us from adding any new secrets to our project.

**Are you currently working around this issue?**
We are not at the moment, if we have to re-approach secrets we will most properly move away from AWS all together and use something like VAULT, but we would prefer not to and use the standard functionality supplied by ECS/FARGATE.

Start by reviewing the Fargate/ECS container-definition limit and the request to increase it from 32 KB to 64 KB. Check whether standard ECS/Fargate behavior can support the larger definition while retaining the current secrets and SSM parameter approach. Done means container definitions up to 64 KB are accepted without requiring the reported workaround.

Written by the indexing model from the issue text.