A few changes to download.py related to troubleshooting Cloud Storage failures when writing files.
Updated cloud storage bucket names.
Removed try block around finalize statement for download files.
Always retry an attempt at retrieving a records "chunk" if the initial attempt fails.
Implemented exponential-delay query retries for individual record "chunk" download retrieval tasks, tracking of task re-enqueue events across task processes and enforcement of a maximum number of task re-enqueues, and notification emails to users when their download requests fail.