Add a sun.management.JMXConnectorServer perf counter to track its state

The sun.management.JMXConnectorServer.<counter>.<key> perf counters are not updated when the remote management agent is stopped.

It is no longer possible to connect to the remote agent, but the counters are still in the same state.
We were hoping to use these counters in JMC to be able to know the state of the remote agent.
(See also JDK-8023093)


Repro:


$>jcmd 9568 PerfCounter.print | grep sun.management

$>jcmd 9568 ManagementAgent.start_local
9568:
Command executed successfully

$>jcmd 9568 PerfCounter.print | grep sun.management
sun.management.JMXConnectorServer.address="service:jmx:rmi://127.0.0.1/stub/rO0ABXNyAC5qYXZheC5tYW5hZ2VtZW50LnJlbW90ZS5ybWkuUk1JU2VydmVySW1wbF9TdHViAAAAAAAAAAICAAB4cgAaamF2YS5ybWkuc2VydmVyLlJlbW90ZVN0dWLp/tzJi+FlGgIAAHhyABxqYXZhLnJtaS5zZXJ2ZXIuUmVtb3RlT2JqZWN002G0kQxhMx4DAAB4cHc5AAtVbmljYXN0UmVmMgAADjEwLjE2MS4xOTAuMTY3AADsmGclwEXuSqnKIf2SqQAAAUxQM0FfgAEAeA=="

$>jcmd 9568 ManagementAgent.start jmxremote.port=7091 jmxremote.authenticate=false jmxremote.ssl=false
9568:
Command executed successfully

$>jcmd 9568 PerfCounter.print | grep sun.management
sun.management.JMXConnectorServer.0.authenticate="false"
sun.management.JMXConnectorServer.0.remoteAddress="service:jmx:rmi:///jndi/rmi://klara01:7091/jmxrmi"
sun.management.JMXConnectorServer.0.ssl="false"
sun.management.JMXConnectorServer.0.sslNeedClientAuth="false"
sun.management.JMXConnectorServer.0.sslRegistry="false"
sun.management.JMXConnectorServer.address="service:jmx:rmi://127.0.0.1/stub/rO0ABXNyAC5qYXZheC5tYW5hZ2VtZW50LnJlbW90ZS5ybWkuUk1JU2VydmVySW1wbF9TdHViAAAAAAAAAAICAAB4cgAaamF2YS5ybWkuc2VydmVyLlJlbW90ZVN0dWLp/tzJi+FlGgIAAHhyABxqYXZhLnJtaS5zZXJ2ZXIuUmVtb3RlT2JqZWN002G0kQxhMx4DAAB4cHc5AAtVbmljYXN0UmVmMgAADjEwLjE2MS4xOTAuMTY3AADsmGclwEXuSqnKIf2SqQAAAUxQM0FfgAEAeA=="

$>jcmd 9568 ManagementAgent.stop
9568:
Command executed successfully

$>jcmd 9568 PerfCounter.print | grep sun.management
sun.management.JMXConnectorServer.0.authenticate="false"
sun.management.JMXConnectorServer.0.remoteAddress="service:jmx:rmi:///jndi/rmi://klara01:7091/jmxrmi"
sun.management.JMXConnectorServer.0.ssl="false"
sun.management.JMXConnectorServer.0.sslNeedClientAuth="false"
sun.management.JMXConnectorServer.0.sslRegistry="false"
sun.management.JMXConnectorServer.address="service:jmx:rmi://127.0.0.1/stub/rO0ABXNyAC5qYXZheC5tYW5hZ2VtZW50LnJlbW90ZS5ybWkuUk1JU2VydmVySW1wbF9TdHViAAAAAAAAAAICAAB4cgAaamF2YS5ybWkuc2VydmVyLlJlbW90ZVN0dWLp/tzJi+FlGgIAAHhyABxqYXZhLnJtaS5zZXJ2ZXIuUmVtb3RlT2JqZWN002G0kQxhMx4DAAB4cHc5AAtVbmljYXN0UmVmMgAADjEwLjE2MS4xOTAuMTY3AADsmGclwEXuSqnKIf2SqQAAAUxQM0FfgAEAeA=="