Memory leak due to no stop for IpNeighborMonitor. am: 93e59ee726

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11910263

Change-Id: I4cfe32fab474ba9bab5e96a90329ad52e87eba77
diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index 5239947..c436be2 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -1322,6 +1322,7 @@
     class UnavailableState extends State {
         @Override
         public void enter() {
+            mIpNeighborMonitor.stop();
             mLastError = TetheringManager.TETHER_ERROR_NO_ERROR;
             sendInterfaceState(STATE_UNAVAILABLE);
         }