[BUG] OS crashes if region is not provided during instance principle configuration

[IshaGirdhar]

What is the bug?

With OS 2.7.0, once the plugin is installed when the config is provided for the instance principle, if the region is omitted, OS crashes with this error.

[ERROR][o.o.b.OpenSearchUncaughtExceptionHandler] [opensearch-es-master-0] fatal error in thread [opensearch[opensearch-es-master-0][snapshot][T#1]], exiting
java.lang.ExceptionInInitializerError: null
	at com.oracle.bmc.Region.getRegionAndRegisterIfNecessary(Region.java:630) ~[?:?]
fatal error in thread [opensearch[opensearch-es-master-0][snapshot][T#1]], exiting
	at com.oracle.bmc.Region.fromRegionCodeOrId(Region.java:439) ~[?:?]

How can one reproduce the bug?

1. Install standalone OS 2.7.0
2. Install this plugin
3. Configure the repository with instance principle
   PUT /_snapshot/oci_repository
   {
   "type": "oci",
   "settings": {
   "client": "default",
   "endpoint": ,
   "bucket": "empty1",
   "namespace": "empty2",
   "bucket_compartment_id": "empty3",
   "useInstancePrincipal": true,
   "forceBucketCreation" : true
   }
   }

What is the expected behavior?

Expect an error if region is not provided, but OS should not crash

What is your host/environment?

OpenSearch: 2.7.0
OS : Oracle-Linux-7.9-2022

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Do you have any additional context?

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[dblock]

[Triage -- attendees 1, 2, 3, 4, 5, 6, 7]

Looks like a valid problem.