Store loopback addresses in a Set, not array.

Order is not important, presence of ipv4 and ipv6 loopback addresses
is tests.

This does not fix test.

Bug: 288266620
Test: CtsLibcoreTestCases:libcore.java.net.SocketTest
Change-Id: I75157d04e4042915215605995973c5263759cb1c
1 file changed