Search usage tests used wrong http code assertion, probably a dev change leftover (#3924)

Author: Mpdreamz

src/Tests/Tests/Search/SearchUsageTestBase.cs

@@ -23,7 +23,7 @@ public abstract class SearchUsageTestBase
 		protected SearchUsageTestBase(ReadOnlyCluster cluster, EndpointUsage usage) : base(cluster, usage) { }
 
 		protected override bool ExpectIsValid => true;
-		protected override int ExpectStatusCode => 201;
+		protected override int ExpectStatusCode => 200;
 		protected override HttpMethod HttpMethod => HttpMethod.POST;
 		protected override string UrlPath => "/project/_search";