steps towards getting ECSRunLauncher working
I started this thinking it would be an easy fix but its a bit more involved than expected. I belive this at least moves things in the right direction.
Would love to have this commandeered, or I can land as a small step forward.
Test Plan: Added test for at least ensuring it can init
Reviewed By: max
Differential Revision: https://dagster.phacility.com/D4772