RANGER-5480: fix unit tests failure with error ConcurrentModificationException

Author: mneethiraj

agents-common/src/main/java/org/apache/ranger/plugin/model/RangerPolicy.java

@@ -921,7 +921,13 @@ public RangerPolicyItem() {
         }
 
         public RangerPolicyItem(RangerPolicyItem other) {
-            this(other.accesses, other.users, other.groups, other.roles, other.conditions, other.delegateAdmin);
+            this.accesses   = other.accesses == null ? new ArrayList<>() : new ArrayList<>(other.accesses);
+            this.users      = other.users == null ? new ArrayList<>() : new ArrayList<>(other.users);
+            this.groups     = other.groups == null ? new ArrayList<>() : new ArrayList<>(other.groups);
+            this.roles      = other.roles == null ? new ArrayList<>() : new ArrayList<>(other.roles);
+            this.conditions = other.accesses == null ? new ArrayList<>() : new ArrayList<>(other.conditions);
+
+            setDelegateAdmin(other.delegateAdmin);
         }
 
         public RangerPolicyItem(List<RangerPolicyItemAccess> accessTypes, List<String> users, List<String> groups, List<String> roles, List<RangerPolicyItemCondition> conditions, Boolean delegateAdmin) {