Stop creating threads for tethering.

Use the passed in looper and save threads.

Change-Id: I6db04ef64e339a5fb2b71e9fb1da32e2d600447c
diff --git a/services/java/com/android/server/ConnectivityService.java b/services/java/com/android/server/ConnectivityService.java
index fa06244..fc20d96 100644
--- a/services/java/com/android/server/ConnectivityService.java
+++ b/services/java/com/android/server/ConnectivityService.java
@@ -320,7 +320,7 @@
             }
         }
 
-        mTethering = new Tethering(mContext);
+        mTethering = new Tethering(mContext, mHandler.getLooper());
         mTetheringConfigValid = (((mNetTrackers[ConnectivityManager.TYPE_MOBILE_DUN] != null) ||
                                   !mTethering.isDunRequired()) &&
                                  (mTethering.getTetherableUsbRegexs().length != 0 ||