[apache#1460] feat(iceberg): Update deafult distribution to none.

api/src/main/java/com/datastrato/gravitino/rel/expressions/distributions/Distributions.java

@@ -13,7 +13,7 @@ public class Distributions {
 
   // NONE is used to indicate that there is no distribution.
   public static final Distribution NONE =
-      new DistributionImpl(Strategy.HASH, 0, Expression.EMPTY_EXPRESSION);
+      new DistributionImpl(Strategy.NONE, 0, Expression.EMPTY_EXPRESSION);
 
   /**
    * Create a distribution by evenly distributing the data across the number of buckets.

api/src/main/java/com/datastrato/gravitino/rel/expressions/distributions/Strategy.java

@@ -18,6 +18,7 @@
  * </ul>
  */
 public enum Strategy {
+  NONE,
   HASH,
   RANGE,
   EVEN;

common/src/main/java/com/datastrato/gravitino/dto/rel/DistributionDTO.java

@@ -23,7 +23,7 @@
 public class DistributionDTO implements Distribution {
 
   public static final DistributionDTO NONE =
-      new Builder().withStrategy(Strategy.HASH).withNumber(0).withArgs(EMPTY_ARGS).build();
+      new Builder().withStrategy(Strategy.NONE).withNumber(0).withArgs(EMPTY_ARGS).build();
 
   // Distribution strategy/method
   private final Strategy strategy;