[ECS] [ECR] [request]: PrivateLink for FIPS ECS and ECR endpoints

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**Tell us about your request**
What do you want us to build?

In regions including us-east-1, PrivateLink endpoints for ECS and ECR exist however, there are no PrivateLink endpoints for the FIPS ECS and FIPS ECR endpoints.

Examples

These endpoints exist:

* ecs-fips.us-east-1.amazonaws.com
* ecr-fips.us-east-1.amazonaws.com
* *.dkr.ecr-fips.us-east-1.amazonaws.com (where * is an AWS account number)

Nothing like these PrivateLink VPC endpoint services exist:

* com.amazonaws.us-east-1.ecs-fips
* com.amazonaws.us-east-1.ecr-fips
* com.amazonaws.us-east-1.ecr-fips.dkr.*

**Which service(s) is this request for?**
ECS and ECR

**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.

Having PrivateLink for FIPS ECS and ECR endpoints would enable us to use Privatelink for ECS and ECR without causing TLS v1.0 to be an available option in a VPC.

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

N/A - no solution that covers all the requirements is available.

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

These PrivateLink VPC endpoints exist:

* com.amazonaws.us-east-1.codebuild-fips
* com.amazonaws.us-east-1.codecommit-fips
* com.amazonaws.us-east-1.elasticfilesystem-fips
* com.amazonaws.us-east-1.git-codecommit-fips
* com.amazonaws.us-east-1.license-manager-fips
* com.amazonaws.us-east-1.rekognition-fips
* com.amazonaws.us-east-1.sagemaker-runtime-fips
* com.amazonaws.us-east-1.sms-fips

References

#2 #20 #132

**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.)

Start by reviewing the requested ECS and ECR FIPS endpoint service names and the related issues #2, #20, and #132. Confirm the PrivateLink and FIPS requirements with AWS service documentation; done means the requested ECS, ECR, and ECR Docker VPC endpoint services are available without exposing TLS 1.0.

Written by the indexing model from the issue text.