DO NOT MERGE Sanitize WifiConfigs

Do this both on input from apps (giving error) and between wifi and
ConnectivityService (ignoring bad data).  This means removing all
addresses beyond the first and all routes but the first default and
the implied direct-connect routes.

We do this because the user can't monitor the others (no UI), their
support wasn't intended, they allow redirection of all traffic
without user knowledge and they allow circumvention of legacy VPNs.

This should not move forward from JB as it breaks IPv6 and K has
a more resilient VPN.

Bug:12663469
Change-Id: I80912cc08ffa1e4b63008c94630006cf316e7a64