Repository GCS Plugin makes the elasticsearch crash on startup when client's proxy settings are specified in elasticsearch.yml.

[jlr-sharma-yash]

Elasticsearch Version

8.0

Installed Plugins

No response

Java Version

bundled

OS Version

win10

Problem Description

I am using GCP plugin with Elasticsearch 8.0 and it seems that the settings that are specified in the documentation here are not available to use in Elasticsearch. I have further gone into investigation to investigate GCS repository plugin and below are my observations:
The settings are declared in GoogleCloudStorageClientSettings.java class here but they are not loaded in the implementation getSettings() method here.
Due to this elasticsearch.bat is throwing error and exiting instead of starting Elasticsearch.

Steps to Reproduce

1. Specify the below settings in elasticsearch.yml:
   gcs.client.default:
   proxy.host: "abc.com"
   proxy.port: 80
   proxy.type: "http"
2. Start elasticsearch.bat and this will generate java.lang.IllegalArgumentException: unknown setting [gcs.client.default.proxy.host] please check that any required plugins are installed, or check the breaking changes documentation for removed settings followed by exiting the bat script.

Logs (if relevant)

@KarenSumner @liladler Could you please help prioritize of fixing this bug?

[elasticmachine]

Pinging @elastic/es-distributed (Team:Distributed)

[liladler]

Hi @arteam, @jlr-sharma-yash tried to test the new support for proxy settings and seeing the following issue.
Is there anything missing? any thoughts?