[ECS] [request]: UpdateService action should have the ability to update tags

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**Tell us about your request**
Look at [CreateService](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_CreateService.html#API_CreateService_RequestSyntax) action parameters. It allows to specify service tags using the [tags](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_CreateService.html#ECS-CreateService-request-tags) parameter.

Now look at [UpdateService](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_UpdateService.html#API_UpdateService_RequestSyntax) action parameters. As you can see it doesn't have a `tags` parameter and doesn't allow to update tags directly from this action. Nevertheless, the `Update Service` form from AWS Console allows to update service tags:

I suppose the ability to update tags should be added to [UpdateService](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_UpdateService.html#API_UpdateService_RequestSyntax) action.

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

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
I'm writing a deploy script and I noticed that I can create an ECS service with tags but I can't update them directly from [UpdateService](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_UpdateService.html#API_UpdateService_RequestSyntax) action. I don't want to use [TagResource](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_TagResource.html), and [UntagResource](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_UntagResource.html) actions for update tags because they slow down deployment. So, will be better to update tags directly from [UpdateService](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_UpdateService.html#API_UpdateService_RequestSyntax) action.

**Are you currently working around this issue?**
I just added the comment about this problem to a configuration file.

**Additional context**
No.

**Attachments**
No.

Start by comparing the AWS ECS CreateService and UpdateService API request syntax, then review the linked TagResource and UntagResource actions. The issue names no repository files or tests; done would mean UpdateService can update service tags directly, but the implementation scope is not defined here.

Written by the indexing model from the issue text.