RFR [9] 7155591: test/java/net/MulticastSocket/SetOutgoingIf.java fails on macOS

[Chris Hegarty]

This is a test-only change.

This is one of the last remaining networking tests that fails when
an Apple Peer-to-Peer interface is available on the host machine.
The changes minimally update the test to use the new test library
Network configuration probe ( centralises and filters platform
specific interfaces ).

http://cr.openjdk.java.net/~chegar/7155591/

-Chris.