Fix system server restart

Change-Id: Ia0b5e337726566ebc96901dadda3fc67eb967755

wifi/java/android/net/wifi/WifiWatchdogStateMachine.java

@@ -881,6 +881,9 @@ public class WifiWatchdogStateMachine extends StateMachine {
             //test to avoid any wifi connectivity issues
             loge("ARP test initiation failure: " + se);
             success = true;
+        } catch (IllegalArgumentException e) {
+            // ArpPeer throws exception for IPv6 address
+            success = true;
         }
 
         return success;