With this commit we start passing the outpost arn (if it's present) to EBS.
Before this commit, when the request came from an outpost instance,
we would ask the EBS to create the volume in the parent AZ, which is not
the expected behavior.

In order to determine if we're running in an outpost instance, we use
the ec2 instance metadata "outpost-arn". It returns a '404' for
non-outpost instances or the outpost-arn as string otherwise. Now we
include it in the topology requiment and pass it along to CreateVolume
request if it's present.

Automated e2e tests can be considerd impossible for this case as getting
an outpost rack is not an easy task.

Create volumes in outpost for outpost instances

Add overlay for ECR images

Release v0.7.0