JFR JSON report's bytesPerSecond is incorrectly calculated

JFR JSON report's bytesPerSecond in network section is incorrectly calculated and always equals countPerSecond when it should not.

JFR JSON report includes bytesPerSecond key and countPerSecond key to indicate how many packets/how much bytes were sent/received. However, when calculating bytes per second, it reads totalCount record value instead of totalSize.