Cleanup modifyRoutes

This is no longer used out of this file, and should not be.

Test: Build
Change-Id: I531191b4afbda39a5fbaf1f483d13068f86d17f1
Merged-In: Ief0a79883bcc2c5493807c548cb71ef655abed23
diff --git a/staticlibs/client-libs/netd/com/android/net/module/util/NetdUtils.java b/staticlibs/client-libs/netd/com/android/net/module/util/NetdUtils.java
index d99eedc..1d8b4eb 100644
--- a/staticlibs/client-libs/netd/com/android/net/module/util/NetdUtils.java
+++ b/staticlibs/client-libs/netd/com/android/net/module/util/NetdUtils.java
@@ -258,7 +258,7 @@
     }
 
     /** Add or remove |route|. */
-    public static void modifyRoute(final INetd netd, final ModifyOperation op, final int netId,
+    private static void modifyRoute(final INetd netd, final ModifyOperation op, final int netId,
             final RouteInfo route) {
         final String ifName = route.getInterface();
         final String dst = route.getDestination().toString();