[#1546] fix(lakehouse-iceberg): fix create Iceberg table failed if co…

…mment is null (#1653)

### What changes were proposed in this pull request?
remove reserveProperties logic from CreateTableRequest since reserved
properties is handled by property system

### Why are the changes needed?

1. when build IcebergTable, comment equals to null is checked when
comment added to properties .
```
      if (null != comment) {
        icebergTable.properties.putIfAbsent(ICEBERG_COMMENT_FIELD_NAME, comment);
      }
```
2. when build CreateTableRequest, the previous implement remove all
reserved properties from property map including comment, and then add
comment to map, the bug happens, not checking the null, but this overall
code is redundant


Fix: #1546 

### Does this PR introduce _any_ user-facing change?
no

### How was this patch tested?
add UT

catalogs/catalog-lakehouse-iceberg/src/main/java/com/datastrato/gravitino/catalog/lakehouse/iceberg/IcebergTable.java

@@ -9,7 +9,6 @@
 import com.datastrato.gravitino.catalog.lakehouse.iceberg.converter.FromIcebergSortOrder;
 import com.datastrato.gravitino.catalog.lakehouse.iceberg.converter.ToIcebergPartitionSpec;
 import com.datastrato.gravitino.catalog.lakehouse.iceberg.converter.ToIcebergSortOrder;
-import com.datastrato.gravitino.catalog.lakehouse.iceberg.ops.IcebergTableOpsHelper;
 import com.datastrato.gravitino.catalog.rel.BaseTable;
 import com.datastrato.gravitino.meta.AuditInfo;
 import com.google.common.collect.Maps;
@@ -45,16 +44,12 @@ private IcebergTable() {}
 
   public CreateTableRequest toCreateTableRequest() {
     Schema schema = ConvertUtil.toIcebergSchema(this);
-
-    Map<String, String> resultProperties =
-        Maps.newHashMap(IcebergTableOpsHelper.removeReservedProperties(properties));
-    resultProperties.putIfAbsent(ICEBERG_COMMENT_FIELD_NAME, comment);
     CreateTableRequest.Builder builder =
         CreateTableRequest.builder()
             .withName(name)
             .withLocation(location)
             .withSchema(schema)
-            .setProperties(resultProperties)
+            .setProperties(properties)
             .withPartitionSpec(ToIcebergPartitionSpec.toPartitionSpec(schema, partitioning))
             .withWriteOrder(ToIcebergSortOrder.toSortOrder(schema, sortOrders));
     return builder.build();

catalogs/catalog-lakehouse-iceberg/src/main/java/com/datastrato/gravitino/catalog/lakehouse/iceberg/ops/IcebergTableOpsHelper.java

@@ -28,9 +28,7 @@
 import com.google.common.collect.Lists;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
-import java.util.stream.Collectors;
 import javax.ws.rs.NotSupportedException;
 import lombok.Getter;
 import lombok.Setter;
@@ -309,12 +307,6 @@ public IcebergTableChange buildIcebergTableChanges(
     return icebergTableChange;
   }
 
-  public static Map<String, String> removeReservedProperties(Map<String, String> createProperties) {
-    return createProperties.entrySet().stream()
-        .filter(entry -> !IcebergReservedProperties.contains(entry.getKey()))
-        .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
-  }
-
   /**
    * Gravitino only supports single-level namespace storage management, which differs from Iceberg.
    * Therefore, we need to handle this difference here.

integration-test/src/test/java/com/datastrato/gravitino/integration/test/catalog/lakehouse/iceberg/CatalogIcebergIT.java

@@ -326,6 +326,21 @@ void testOperationIcebergSchema() {
     Assertions.assertTrue(schemaNames.contains(schemaName));
   }
 
+  @Test
+  void testCreateTableWithNullComment() {
+    ColumnDTO[] columns = createColumns();
+    NameIdentifier tableIdentifier =
+        NameIdentifier.of(metalakeName, catalogName, schemaName, tableName);
+
+    TableCatalog tableCatalog = catalog.asTableCatalog();
+    Table createdTable =
+        tableCatalog.createTable(tableIdentifier, columns, null, null, null, null, null);
+    Assertions.assertNull(createdTable.comment());
+
+    Table loadTable = tableCatalog.loadTable(tableIdentifier);
+    Assertions.assertNull(loadTable.comment());
+  }
+
   @Test
   void testCreateAndLoadIcebergTable() {
     // Create table from Gravitino API