ethernet: ignore NUD failures for static ip configurations

Bug: 245064497
Test: atest EthernetManagerTest
Change-Id: Ib14f444b219e744226f5b58f5f61e38318d2f9a0
diff --git a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
index 2196bf8..48d68d7 100644
--- a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
+++ b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
@@ -558,6 +558,13 @@
 
         void updateNeighborLostEvent(String logMsg) {
             Log.i(TAG, "updateNeighborLostEvent " + logMsg);
+            if (mIpConfig.getIpAssignment() == IpAssignment.STATIC) {
+                // Ignore NUD failures for static IP configurations, where restarting the IpClient
+                // will not fix connectivity.
+                // In this scenario, NetworkMonitor will not verify the network, so it will
+                // eventually be torn down.
+                return;
+            }
             // Reachability lost will be seen only if the gateway is not reachable.
             // Since ethernet FW doesn't have the mechanism to scan for new networks
             // like WiFi, simply restart.