config(ingest/rest): Update rest sink defaults to retry more often

[asikowitz]

Pretty significant changes:

• Attempts retries on 500s. We get these a lot, potentially when gms goes down
• Increases default retries attempts by one. I believe this will turn wait times from [0, 2, 4] to [0, 2, 4, 8]

This does mean that if you're trying to ingest to a datahub instance that's completely down, it's going to a take a lot longer for that ingestion to run.

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub