Fix CompareOrUpdateResult key in Dhcp6AddrRegTracker

The key for the CompareOrUpdateResult was an Integer, which was the
hash of the address and prefix length. This is not guaranteed to be
unique.

This change replaces the Integer key with a Pair<InetAddress, Integer>
to ensure uniqueness.

Test: TH
Flag: EXEMPT mainline
Change-Id: I0f00cd7fd5020b109aa04118bbcf7d5d77a60287
1 file changed