fix(helm): use correct templating logic for compute log manager

Summary:
Use correct if/else if constructs. While adding tests, it seems like
we didn't template skipEmptyFiles in the s3 compute log manager.
Correct that as well.

Test Plan: pytest

Reviewers: johann, alangenfeld

Reviewed By: johann

Differential Revision: https://dagster.phacility.com/D9080