Replace the way to add legacy routing

ConnectivityService is going to become a mainline module which
is not able to access hidden API. Thus, replace the usage from
NMS to INetd.

Bug: 170598012
Test: atest FrameworksNetTests ConnectivityManagerLegacyTest
Change-Id: Ice1bd1effab26555917bc1766354aeaebd41ad66

services/core/java/com/android/server/ConnectivityService.java

@@ -1917,10 +1917,13 @@ public class ConnectivityService extends IConnectivityManager.Stub
         }
         if (DBG) log("Adding legacy route " + bestRoute +
                 " for UID/PID " + uid + "/" + Binder.getCallingPid());
+
+        final String dst = bestRoute.getDestinationLinkAddress().toString();
+        final String nextHop = bestRoute.hasGateway()
+                ? bestRoute.getGateway().getHostAddress() : "";
         try {
-            mNMS.addLegacyRouteForNetId(netId, bestRoute, uid);
-        } catch (Exception e) {
-            // never crash - catch them all
+            mNetd.networkAddLegacyRoute(netId, bestRoute.getInterface(), dst, nextHop , uid);
+        } catch (RemoteException | ServiceSpecificException e) {
             if (DBG) loge("Exception trying to add a route: " + e);
             return false;
         }