[BUG] Error adding "cluster.routing.allocation.balanced_shards_allocator.allocator_timeout" setting

[RamakrishnaChilaka]

Describe the bug

Unable to set "cluster.routing.allocation.balanced_shards_allocator.allocator_timeout" setting in 2.13, while the same works in 2.15.

Related component

Other

To Reproduce

1. Clone openserch
2. checkout to 2.13
3. Try to add this setting curl --location --request PUT 'http://localhost:9200/_cluster/settings' \ --header 'Content-Type: application/json' \ --data '{ "persistent" : { "cluster.routing.allocation.balanced_shards_allocator.allocator_timeout" : "30s" } }'
4. Fails with {"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"persistent setting [cluster.routing.allocation.balanced_shards_allocator.allocator_timeout], not recognized"}],"type":"illegal_argument_exception","reason":"persistent setting [cluster.routing.allocation.balanced_shards_allocator.allocator_timeout], not recognized"},"status":400}%

Expected behavior

The same works in 2.15

bcd07443cc66 % curl --location --request PUT 'http://localhost:9200/_cluster/settings' \
--header 'Content-Type: application/json' \
--data '{
  "persistent" : {
    "cluster.routing.allocation.balanced_shards_allocator.allocator_timeout" : "30s"
  }
}'
{"acknowledged":true,"persistent":{"cluster":{"routing":{"allocation":{"balanced_shards_allocator":{"allocator_timeout":"30s"}}}}},"transient":{}}%

Additional Details

Plugins
No plugin is enabled

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Host/Environment (please complete the following information):

• OS: macos
• Version 2.13

[shwetathareja]

@RamakrishnaChilaka this setting is present from OpenSearch 2.17 onwards.
Pull request - #15239