v0 and v1 data cleanup

[jhamman]

We've been pushing hard on both v0 and v1 lately. As these pushes wrap up, we've likely left quite of bit of data on s3 and gcs that needs to be cleaned up.

@orianac and @tcchiao, can you each provide a short writeup below outlining the data we want to keep/delete from v0 and v1 respectively?