Adding a component config to take down single homed host ports when all uplinks are lost.

In addition:
   - handle port updates that may be lost if mastership changes at same time
   - fix javadoc in DeviceService

Change-Id: I032909e8ab9564cf9c978b1d66abd3ab32c814d7
diff --git a/app/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java b/app/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
index 9063015..094d287 100644
--- a/app/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
+++ b/app/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
@@ -1270,7 +1270,7 @@
             srManager.flowObjectiveService.forward(deviceId, obj);
         });
 
-        srManager.getPairLocalPorts(deviceId).ifPresent(port -> {
+        srManager.getPairLocalPort(deviceId).ifPresent(port -> {
             ForwardingObjective pairFwdObj;
             // Do not punt ARP packets from pair port
             pairFwdObj = arpFwdObjective(port, false, PacketPriority.CONTROL.priorityValue() + 1)