[IcebergIO]Create tables with Iceberg Table properties

Author: tarun-google

sdks/java/io/iceberg/src/main/java/org/apache/beam/sdk/io/iceberg/IcebergWriteSchemaTransformProvider.java

@@ -125,8 +125,9 @@ public static Builder builder() {
     public abstract @Nullable List<String> getPartitionFields();
 
     @SchemaFieldDescription(
-        "Iceberg table properties to be set on the table when it is created,"
-            + "For more information on table properties, please visit https://iceberg.apache.org/docs/latest/configuration/#table-properties.")
+        "Iceberg table properties to be set on the table when it is created.\n"
+            + "For more information on table properties,"
+            + " please visit https://iceberg.apache.org/docs/latest/configuration/#table-properties.")
     public abstract @Nullable Map<String, String> getTableProperties();
 
     @AutoValue.Builder

sdks/java/io/iceberg/src/main/java/org/apache/beam/sdk/io/iceberg/RecordWriterManager.java

@@ -293,6 +293,7 @@ private Table getOrCreateTable(IcebergDestination destination, Schema dataSchema
     @Nullable IcebergTableCreateConfig createConfig = destination.getTableCreateConfig();
     PartitionSpec partitionSpec =
         createConfig != null ? createConfig.getPartitionSpec() : PartitionSpec.unpartitioned();
+    // Ensure table properties are not null, Iceberg's createTable does not accept null values.
     Map<String, String> tableProperties =
         (createConfig != null && createConfig.getTableProperties() != null)
             ? createConfig.getTableProperties()