What/Why

What are you proposing?

Currently, AD Extension creates a metedata index

ANOMALY_DETECTORS_INDEX = ".opendistro-anomaly-detectors";

As per 3.x version of OpenSearch only the system index should start with .. To resolve this warning we can change the name of the index to opensearch-anomaly-detectors but this will break the backward compatibility.

What problems are you trying to solve?

index name .opendistro-anomaly-detectors starts with a dot '.', in the next major version

Are there any breaking changes to the API

Backward compatibility needs to be handled with this new change of index name.