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: I1789b60857060044ef09b9cd34d652ff9b852f84
(cherry picked from commit 257c24ea092c903dcb45a40796eb02d5681e053c)
(cherry picked from commit 9d4b173377181941dfe39137ae0bb33cd9469292)
(cherry picked from commit 5e5556837835152412a59a57e1362cd52ef89827)
(cherry picked from commit 01a74486c0e79e772f1b4a1149dc3c7a585a36f5)