Issue with Multi terms aggregation with Boolean field

[bsehra]

@bsehra

ElasticsearchClientSettings settings = new();
                settings = new ElasticsearchClientSettings(
                    singleNodeConnectionPool)
                    .DefaultIndex(index)

@flobernd and @Ignacio_Vera , I think I've gotten to the root cause of this issue. I believe there's an issue executing queries with multi terms, where it fails to get the default target index name configured in the client's connection settings but it works when we explicitly provide index name with the search requests.