[Backport 2.x] Adding Index Settings validation before starting replication

[opensearch-trigger-bot]

Backport 93b43f4 from #461

[codecov-commenter]

Codecov Report

Merging #470 (e1eaf54) into 2.x (5ab5469) will decrease coverage by 2.89%.
The diff coverage is 100.00%.

❗ Current head e1eaf54 differs from pull request most recent head 1a1a2e4. Consider uploading reports for the commit 1a1a2e4 to get more accurate results

@@             Coverage Diff              @@
##                2.x     #470      +/-   ##
============================================
- Coverage     73.32%   70.43%   -2.90%     
+ Complexity      985      944      -41     
============================================
  Files           141      141              
  Lines          4562     4576      +14     
  Branches        504      506       +2     
============================================
- Hits           3345     3223     -122     
- Misses          905     1034     +129     
- Partials        312      319       +7     

Impacted Files	Coverage Δ
...tion/action/index/TransportReplicateIndexAction.kt	76.66% <100.00%> (+2.59%)	⬆️
.../org/opensearch/replication/util/ValidationUtil.kt	62.74% <100.00%> (+6.93%)	⬆️
...earch/replication/action/stats/NodeStatsRequest.kt	33.33% <0.00%> (-66.67%)	⬇️
...arch/replication/metadata/UpdateMetadataRequest.kt	40.90% <0.00%> (-59.10%)	⬇️
...eplication/action/stats/LeaderNodeStatsResponse.kt	42.85% <0.00%> (-57.15%)	⬇️
.../replication/action/replay/ReplayChangesRequest.kt	50.00% <0.00%> (-50.00%)	⬇️
...replication/action/index/ReplicateIndexResponse.kt	33.33% <0.00%> (-33.34%)	⬇️
...tion/action/index/block/UpdateIndexBlockRequest.kt	35.00% <0.00%> (-30.00%)	⬇️
...replication/action/stats/AutoFollowStatsRequest.kt	71.42% <0.00%> (-28.58%)	⬇️
...opensearch/replication/seqno/RemoteClusterStats.kt	73.01% <0.00%> (-26.99%)	⬇️
... and 36 more

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