[Foundation] Set the MaxInputInMemory to match the limit from other B…

…CL classes. Fixes #21537

The MaxInputInMemory property is set by default to be long.MaxValue.
This value is much larger than the one we can find in other BCL classes
such as the HttpContent [max value](https://github.com/microsoft/referencesource/blob/master/System/net/System/Net/Http/HttpContent.cs#L20)
and the MemoryStream [max value](https://github.com/dotnet/runtime/blob/1d1bf92fcf43aa6981804dc53c5174445069c9e4/src/libraries/System.Private.CoreLib/src/System/IO/MemoryStream.cs#L37).

It is important to notice that the HttpContent.MaxValue is used to
limit the value of the MaxResponseContentBufferSize property in the
HttpClient. This means that by making this move we are following the
rest of the BCL.

Fixes #21537

src/Foundation/NSUrlSessionHandler.cs

@@ -217,7 +217,7 @@ void BackgroundNotificationCb (NSNotification obj)
 		}
 #endif
 
-		public long MaxInputInMemory { get; set; } = long.MaxValue;
+		public long MaxInputInMemory { get; set; } = (long) int.MaxValue; // use int.MaxValue since it is the same max value used by both HttpContent and MemoryStream.
 
 		void RemoveInflightData (NSUrlSessionTask task, bool cancel = true)
 		{