CORD-546 Push L3 unicast rules for bgp peers when they are learned

- Change L3 unicast group id/key generation to include src MAC
- Note: Only flows are removed when a peer is gone
  since the group may still be referenced by routes announced by peer.
  It does no harm even if the group is not referenced.
- Note: We assume that peer does not move or update IP

Also fix several SR/VR integration issues, including
- Do not push broadcast group for /32

Change-Id: Ifb03601f5341f8b7717ea1fbccbc569b07f66476
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/config/DeviceConfiguration.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/config/DeviceConfiguration.java
index bf8c4d7..932b8ad 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/config/DeviceConfiguration.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/config/DeviceConfiguration.java
@@ -278,6 +278,10 @@
             PortNumber port = entry.getKey();
             Ip4Prefix subnet = entry.getValue();
 
+            if (subnet.prefixLength() == IpPrefix.MAX_INET_MASK_LENGTH) {
+                return;
+            }
+
             if (subnetPortMap.containsKey(subnet)) {
                 subnetPortMap.get(subnet).add(port);
             } else {