Remove last NetworkStack usage of hidden APIs

Includes various small changes to stop using hidden APIs

Test: make NetworkStack
Test: flashed, booted, WiFi and tethering working
Bug: 112869080
Change-Id: Id2830795a444f484b377ed6437435a1cd833697a
diff --git a/services/core/java/com/android/server/IpSecService.java b/services/core/java/com/android/server/IpSecService.java
index 371276f..126bf65 100644
--- a/services/core/java/com/android/server/IpSecService.java
+++ b/services/core/java/com/android/server/IpSecService.java
@@ -44,7 +44,7 @@
 import android.net.Network;
 import android.net.NetworkUtils;
 import android.net.TrafficStats;
-import android.net.shared.NetdService;
+import android.net.util.NetdService;
 import android.os.Binder;
 import android.os.IBinder;
 import android.os.ParcelFileDescriptor;