server: add enhanced routing support

Add support for policy and metric based routing APIs to
NetworkManagementService. This functionality is used for WQE, IMS, and
Android QoS features.

Change-Id: I5e50185c9ac1cf72c9366815c2ecf590842edfca
frameworks/base: IPV6 tethering support

This patch adds two new API calls addUpstreamV6Interface and
removeUpstreamV6Interface to the tethering framework to pass the IPv6
upstream and downstream interfaces to netd if IPv6 is available.
Required to enable ICMPv6 forwarding.

Change-Id: I1f4f6284b2f152d8b4f0fbd02ac5a17f57c71dd7
Merge "frameworks/base: IPV6 tethering support" into jb3