Update merge on refresh and merge on commit defaults in Opensearch (Lucene 9.3)

[reta]

Is your feature request related to a problem? Please describe.
The Apache Lucene 9.3 made merge-on-refresh enabled by default [1].

[1] https://github.com/apache/lucene/pull/921/files

Describe the solution you'd like
The Opensearch merge policy has to be updated in order to accommodate this change.

Describe alternatives you've considered
N/A

Additional context
Related to #3537

[reta]

@nknize fyi

[elfisher]

@reta is there anything we should consider documenting regarding this change? Does it have performance implications for users or anything else we should cover in opensearch.org/docs?

[reta]

@elfisher yes, I will submit the documentation update for 2.1.0 / 2.2.0. Trying to find out the best place for it and not sure 9.3 will be released before 2.1.0 is out. In general, the change should have only positive performance implications, but we are providing the option to disable it.