[BUG] Unhelpful error message initializing OpenSearch Ingestion, OpenSearch sink

[Jon-AtAWS]

See also: https://github.com/opensearch-project/opensearch-java/issues/473

Looks like we maybe fixed this in the java client, but not in the Python client? Or maybe this is a different code path?

I haven't been able to diagnose exactly what's going on and where the failure is. Here's what's in CloudWatch Logs for the OpenSearch sink initialization

2024-02-27T19:37:23.594 [log-pipeline-sink-worker-2-thread-1] WARN  org.opensearch.dataprepper.plugins.sink.opensearch.OpenSearchSink - Failed to initialize OpenSearch sink with a retryable exception. 
org.opensearch.client.opensearch._types.OpenSearchException: Request failed: [security_exception] authentication/authorization failure
	at org.opensearch.client.transport.aws.AwsSdk2Transport.parseResponse(AwsSdk2Transport.java:473) ~[opensearch-java-2.8.1.jar:?]
	at org.opensearch.client.transport.aws.AwsSdk2Transport.executeSync(AwsSdk2Transport.java:392) ~[opensearch-java-2.8.1.jar:?]
	at org.opensearch.client.transport.aws.AwsSdk2Transport.performRequest(AwsSdk2Transport.java:192) ~[opensearch-java-2.8.1.jar:?]
	at org.opensearch.client.opensearch.indices.OpenSearchIndicesClient.exists(OpenSearchIndicesClient.java:507) ~[opensearch-java-2.8.1.jar:?]
	at org.opensearch.dataprepper.plugins.sink.opensearch.index.NoIsmPolicyManagement.checkIfIndexExistsOnServer(NoIsmPolicyManagement.java:50) ~[opensearch-2.6.1.jar:?]
	at org.opensearch.dataprepper.plugins.sink.opensearch.index.AbstractIndexManager.checkAndCreateIndex(AbstractIndexManager.java:268) ~[opensearch-2.6.1.jar:?]
	at org.opensearch.dataprepper.plugins.sink.opensearch.index.AbstractIndexManager.setupIndex(AbstractIndexManager.java:225) ~[opensearch-2.6.1.jar:?]
	at org.opensearch.dataprepper.plugins.sink.opensearch.OpenSearchSink.doInitializeInternal(OpenSearchSink.java:231) ~[opensearch-2.6.1.jar:?]
	at org.opensearch.dataprepper.plugins.sink.opensearch.OpenSearchSink.doInitialize(OpenSearchSink.java:193) ~[opensearch-2.6.1.jar:?]
	at org.opensearch.dataprepper.model.sink.AbstractSink.initialize(AbstractSink.java:52) ~[data-prepper-api-2.6.1.jar:?]
	at org.opensearch.dataprepper.pipeline.Pipeline.isReady(Pipeline.java:200) ~[data-prepper-core-2.6.1.jar:?]
	at org.opensearch.dataprepper.pipeline.Pipeline.lambda$execute$2(Pipeline.java:252) ~[data-prepper-core-2.6.1.jar:?]
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) ~[?:?]
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?]
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[?:?]
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[?:?]
	at java.base/java.lang.Thread.run(Thread.java:829) [?:?]

FWIW, my pipeline role has:

		{
			"Action": [
				"es:DescribeDomain",
				"es:*"
			],
			"Resource": "arn:aws:es:us-west-2:OBSCURED:domain/OBSCURED",
			"Effect": "Allow"
		},