Implement CLI for black hole routes

Change-Id: I9bb2aa8641b780cf90dd8a0aefdc57169c02186f
(cherry picked from commit feadacb580e7d2c325453b3afe474049d27d11d8)
diff --git a/app/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java b/app/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
index 5cd1cca..7ace77f 100644
--- a/app/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
+++ b/app/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
@@ -1404,9 +1404,7 @@
     }
 
     /**
-     * Populates a forwarding objective to send packets that miss other high
-     * priority Bridging Table entries to a group that contains all ports of
-     * its subnet.
+     * Block given prefix in routing table.
      *
      * @param address the address to block
      * @param deviceId switch ID to set the rules
@@ -1416,9 +1414,7 @@
     }
 
     /**
-     * Populates a forwarding objective to send packets that miss other high
-     * priority Bridging Table entries to a group that contains all ports of
-     * its subnet.
+     * Unblock given prefix in routing table.
      *
      * @param address the address to block
      * @param deviceId switch ID to set the rules