jfr-connection: Recording close should not throw exception

[dsgrieve]

Description:
Recording close method would throw an exception if the FlightRecorderConnection closeRecording method threw an exception. This is a regression from the microsoft/jfr-streaming code that was contributed.

Existing Issue(s):

Closing a JFR recording may throw an Exception #1410
Testing:

Existing tests were examined and no changes were necessary.

Documentation:

No changes to documentation were needed. However, several methods in FlightRecorderMXBeanConnection stated that the method was not available in Java 8. The javadoc for these methods was changed to more correctly state that the command is not available through the Diagnostic Command MBean.

Outstanding items:

None.

[breedx-splk]

This seems good to me. Maybe it was just an oversight or a mistake, but it does indeed seem odd that it was swallowing the exception for stopRecording() but not closeRecording(). Thanks!