[Refactor] Use Builder pattern instead of constructors for Stats API classes

[sandeshkr419]

Is your feature request related to a problem? Please describe

As a follow-up on #18723, I noticed other stats related classes should also utilize Builder pattern to initialize stats objects.

For example IndexingStats currently has 2 constructors: https://github.com/opensearch-project/OpenSearch/blob/main/server/src/main/java/org/opensearch/index/shard/IndexingStats.java#L191-L246

Stats related classes are exposed as PublicApi, and stats are frequently (or maybe once in a while but need to be) incremented, which causes backward-compatibility to break. This makes it difficult to add new metrics and evolve the API without causing significant disruption for developers who have adopted it. Each new stat forces a major version bump and requires users to update their code, even if they don't need the new metric.

Using this issue to track all such metric/stats classes to adopt to builder pattern and mark the existing public constructors to be on deprecation path.

Reference from SearchStats: #18707

Describe the solution you'd like

• List down all classes to be actioned from stats API / code dive deep
• Create builder pattern for those classes
• Mark existing constructors as deprecated

Related component

Other

Describe alternatives you've considered

No response

Additional context

No response

[pado0]

Hi @sandeshkr419 , can I work on this issue?

[sandeshkr419]

Thanks @pado0 for taking this, feel free to post any questions if you need help.

[pado0]

@sandeshkr419 Thanks for assigning this to me! I’ll reach out if I run into any difficulties. 👍