set new default KeepAlive configurations

Summary:
In this diff, we tune the default keep alive parameter to be the following

```
-Dthrift.rsocket-keep-alive-ms=30000
-Dthrift.rsocket-keep-max-lifetime-ms=3600000
```

Reviewed By: prakashgayasen

Differential Revision: D54496796

fbshipit-source-id: e921d409d5bc01fbcd0f328934fba25cad12fd3c

thrift/lib/java/runtime/src/main/java/com/facebook/thrift/rsocket/client/RSocketRpcClientFactory.java

@@ -38,12 +38,25 @@ public class RSocketRpcClientFactory implements RpcClientFactory {
           System.getProperty(
               "thrift.rsocket-max-frame-size", String.valueOf(FrameLengthCodec.FRAME_LENGTH_MASK)));
 
+  // NOTE: KeepAlive is part of the RSocket Protocols, it is a way of maintaining connections and
+  // detecting broken connections (such as half open connection).
+  //
+  // How KeepAlive works:
+  // * Client periodically pings the server with KeepAliveFrame, server returns ACK immediately.
+  // * Client periodically checks received ACKs.
+  // * If client do not receive KeepAlive ACK after the configured max lifetime, the client closes
+  // the connection.
+  //
+  // KeepAlive Configurations:
+  // thrift.rsocket-keep-alive-ms (or KEEP_ALIVE): the interval of client KeepAlive ping.
+  // thrift.rsocket-keep-max-lifetime-ms (or KEEP_ALIVE_MAX_LIFETIME): time window when client
+  // checks ACKs. During the time window, if no ACK was received, client will close the connection.
   private static final int KEEP_ALIVE =
-      Integer.parseInt(System.getProperty("thrift.rsocket-keep-alive-ms", String.valueOf(-1)));
+      Integer.parseInt(System.getProperty("thrift.rsocket-keep-alive-ms", String.valueOf(30000)));
 
   private static final int KEEP_ALIVE_MAX_LIFETIME =
       Integer.parseInt(
-          System.getProperty("thrift.rsocket-keep-max-lifetime-ms", String.valueOf(-1)));
+          System.getProperty("thrift.rsocket-keep-max-lifetime-ms", String.valueOf(3600000)));
 
   static {
     ReactorHooks.init();