Verify the IP addresses from IPv6-only provisioning look correct.

Currently, the IPv6-only tests in IpClientIntegrationTest check
that there are 3 IPv6 addresses, but not what type of addresses
they are. Check that one is a link-local address, one is a stable
privacy address, and one is a privacy address.

Bug: 152723363
Test: test-only change
Original-Change: https://android-review.googlesource.com/1295491
Merged-In: I285952a9a1476c694e54b6bc27ec757fd5d8eb50
Change-Id: I285952a9a1476c694e54b6bc27ec757fd5d8eb50