Reduce Default Keep-Alive Timeout Value for httpclient

The default Keep-Alive timeout for both HTTP/1.1 and HTTP/2 connection when using the httpclient is currently 1200 seconds.

If an open connection is silently dropped by a server/remote before the 1200 second limit, the client will wait the full duration before dropping the connection. Common tools such as load balancers have far shorter intervals before dropping a client connection in and arond the range of 350-500 seconds.

A more appropriate default value might be 30 seconds.