Merge changes I2292c1cb,I8f60c137 into rvc-dev

* changes:
  Test that IpNeighborMonitor is stopped when IpServer stops.
  Memory leak due to no stop for IpNeighborMonitor.

Tethering/src/android/net/ip/IpServer.java

@@ -1322,6 +1322,7 @@ public class IpServer extends StateMachine {
     class UnavailableState extends State {
         @Override
         public void enter() {
+            mIpNeighborMonitor.stop();
             mLastError = TetheringManager.TETHER_ERROR_NO_ERROR;
             sendInterfaceState(STATE_UNAVAILABLE);
         }

Tethering/tests/unit/src/android/net/ip/IpServerTest.java

@@ -860,6 +860,7 @@ public class IpServerTest {
         verify(mBpfCoordinator).tetherOffloadRuleClear(mIpServer);
         verify(mNetd).tetherOffloadRuleRemove(matches(UPSTREAM_IFINDEX, neighA, macA));
         verify(mNetd).tetherOffloadRuleRemove(matches(UPSTREAM_IFINDEX, neighB, macB));
+        verify(mIpNeighborMonitor).stop();
         resetNetdAndBpfCoordinator();
     }