Change default IMemoryStreamFactory (#5740)

* No longer default to RecyclableMemoryStreamFactory

* Update comment and release notes

Author: stevejgordon

docs/release-notes/release-notes-7.14.0-human.asciidoc

@@ -1 +1,11 @@
+=== MemoryStreamFactory Changes
 
+In this release we have changed the value of DefaultMemoryStreamFactory in ConnectionConfiguration such that a new memory stream is used each time. This behavior is more predictable since instances will not be pooled leading to potentially large long-lived allocations. Instead, instances will be created on demand and once release, may be garbage collected. 
+
+In advanced situations you may wish to configure the previous default and use the RecyclableMemoryStream.
+
+[source,csharp]
+----
+var settings = new ConnectionSettings(new Uri("http://localhost:9200"))
+    .MemoryStreamFactory(RecyclableMemoryStreamFactory.Default);
+----

src/Elasticsearch.Net/Configuration/ConnectionConfiguration.cs

@@ -173,9 +173,8 @@ public abstract class ConnectionConfiguration<T> : IConnectionConfigurationValue
 		private bool _sniffOnStartup;
 		private bool _throwExceptions;
 		private bool _transferEncodingChunked;
-		private IMemoryStreamFactory _memoryStreamFactory = RecyclableMemoryStreamFactory.Default;
+		private IMemoryStreamFactory _memoryStreamFactory = DefaultMemoryStreamFactory;
 		private bool _enableTcpStats;
-		//public static IMemoryStreamFactory Default { get; } = RecyclableMemoryStreamFactory.Default;
 		public static IMemoryStreamFactory DefaultMemoryStreamFactory { get; } = Elasticsearch.Net.MemoryStreamFactory.Default;
 		private bool _enableThreadPoolStats;
 		private bool _enableApiVersioningHeader;
@@ -610,7 +609,7 @@ public T SkipDeserializationForStatusCodes(params int[] statusCodes) =>
 		public T TransferEncodingChunked(bool transferEncodingChunked = true) => Assign(transferEncodingChunked, (a, v) => a._transferEncodingChunked = v);
 
 		/// <summary>
-		/// The memory stream factory to use, defaults to <see cref="RecyclableMemoryStreamFactory.Default"/>
+		/// The memory stream factory to use, defaults to <see cref="Elasticsearch.Net.MemoryStreamFactory.Default"/>
 		/// </summary>
 		public T MemoryStreamFactory(IMemoryStreamFactory memoryStreamFactory) => Assign(memoryStreamFactory, (a, v) => a._memoryStreamFactory = v);