FEATURE REQUEST: Propagate Container Instance and Service Tags to Task

### Summary
Would be great to have the ECS Container Instance, Service and Task Tags to propagate to the container as labels and be able to retrieve the labels from inside the container. Or add the docker daemon labels to the metadata.

### Description
curl $ECS_CONTAINER_METADATA_URI
should display container instance, service and task tags as labels.

Could be used to provide instance specific information to each containers.

Start with the ECS container metadata endpoint at $ECS_CONTAINER_METADATA_URI and review how its response is exposed inside the container. The work is complete when curling that endpoint displays the container instance, service, and task tags as container labels or equivalent metadata.

Written by the indexing model from the issue text.