[ONOS-6508] Copy ImmutableList in DiscreteResourceId constructor to ensure binary serialization formats match across all resource IDs

Change-Id: I7018214a4a25f619363c1b1b53d54b9dfec756e2
diff --git a/core/api/src/main/java/org/onosproject/net/resource/DiscreteResourceId.java b/core/api/src/main/java/org/onosproject/net/resource/DiscreteResourceId.java
index 441fe88..8e51250 100644
--- a/core/api/src/main/java/org/onosproject/net/resource/DiscreteResourceId.java
+++ b/core/api/src/main/java/org/onosproject/net/resource/DiscreteResourceId.java
@@ -32,7 +32,7 @@
     private final ImmutableList<Object> components;
 
     DiscreteResourceId(ImmutableList<Object> components) {
-        this.components = components;
+        this.components = ImmutableList.copyOf(components);
     }
 
     DiscreteResourceId() {