fix(opensearch): Rollover usage events at a file size rather than time-based manner

[darnaut]

The rollover operation rolls an alias over to a new index when the managed index meets one of the rollover conditions. Since the rollover conditions are min_index_age: 1d and min_size: 5gb conditions, the index ends up being rolled over every day since the minimum index age condition will evaluate to true.

Instead of time-based rollover, this changes the rollover condition to only be based on the minimum size.

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

[david-leifker]

Needs schema_version increment