multi-architecture support for containers

**Tell us about your request**
ECR Repositories do support manifest lists, which allows to build and push to ECR multi CPI architecture container images. Reference article: https://aws.amazon.com/blogs/containers/introducing-multi-architecture-container-images-for-amazon-ecr/

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
Current limitation by ContainerRecipe/ImagePipeline is that multi-architecture is not supported to my understanding.

**Are you currently working around this issue?**
Separate ImagePipelines & tagging, held in single ECR repo, makes mess.

Start by reading the linked Amazon ECR multi-architecture container images article and reviewing how ContainerRecipe and ImagePipeline currently handle architectures. Confirm the desired manifest-list flow and how ECR repositories are used today. Done means multi-architecture container images can be built and pushed without separate ImagePipelines and confusing tags.

Written by the indexing model from the issue text.