Notify network observers of route changes.

This reverts commit 20d3f5e856a38ef22851e32d7f9b6a7cd02eb459.

Bug: 9180552
Change-Id: I004448e2f0c731f6ca2c6d3535dc4dd51a622293
diff --git a/server/NetlinkManager.cpp b/server/NetlinkManager.cpp
index 32578a1..1d731ac 100644
--- a/server/NetlinkManager.cpp
+++ b/server/NetlinkManager.cpp
@@ -105,6 +105,7 @@
                                      RTMGRP_LINK |
                                      RTMGRP_IPV4_IFADDR |
                                      RTMGRP_IPV6_IFADDR |
+                                     RTMGRP_IPV6_ROUTE |
                                      (1 << (RTNLGRP_ND_USEROPT - 1)),
          NetlinkListener::NETLINK_FORMAT_BINARY)) == NULL) {
         return -1;