Is this not controlled on the backend? It seems like making this an API option could be problematic.

• Everything that uses the API will need to be updated if you ever want to get rid of the non-presto way of doing things.
• Even after moving everything we know about (and there could be uses we are unaware of), there is nothing to stop new usages.
• If something goes wrong with the presto version and we need to roll back, we now have to make changes to all the clients that have switched over.
• This is not the only way to access the API. In particular, the new task generation code is written in rust, so it is making this call via a rust version of the API.

It seems like having some configuration on the backend that could switch this over might be easier to manage. It could switch over everything at once and if there are problems quickly switch everything back.

@rtimmons is this PR still needed?