Change tetheroffloadjni to tetheringutilsjni

Rename tetheroffloadjni to tetheringutilsjni and move setupRaSocket
jni method from NetUtils into tetheringutilsjni.

Bug: 143195885
Test: -build, flash, boot
      -atest TetheringTests
      -Off/On hotspot with ipv6 upstream

Change-Id: Ib68eb6999bbe2d3ca97e68712f22b105311ef800
diff --git a/Tethering/src/android/net/ip/RouterAdvertisementDaemon.java b/Tethering/src/android/net/ip/RouterAdvertisementDaemon.java
index 4147413..4396cdb 100644
--- a/Tethering/src/android/net/ip/RouterAdvertisementDaemon.java
+++ b/Tethering/src/android/net/ip/RouterAdvertisementDaemon.java
@@ -30,6 +30,7 @@
 import android.net.NetworkUtils;
 import android.net.TrafficStats;
 import android.net.util.InterfaceParams;
+import android.net.util.TetheringUtils;
 import android.system.ErrnoException;
 import android.system.Os;
 import android.system.StructTimeval;
@@ -613,7 +614,7 @@
                     mSocket, SOL_SOCKET, SO_SNDTIMEO, StructTimeval.fromMillis(send_timout_ms));
             Os.setsockoptIfreq(mSocket, SOL_SOCKET, SO_BINDTODEVICE, mInterface.name);
             NetworkUtils.protectFromVpn(mSocket);
-            NetworkUtils.setupRaSocket(mSocket, mInterface.index);
+            TetheringUtils.setupRaSocket(mSocket, mInterface.index);
         } catch (ErrnoException | IOException e) {
             Log.e(TAG, "Failed to create RA daemon socket: " + e);
             return false;