fix to use enum class value for default value in flinkoptions

Author: hehuiyuan

hudi-flink-datasource/hudi-flink/src/main/java/org/apache/hudi/configuration/FlinkOptions.java

@@ -25,13 +25,16 @@
 import org.apache.hudi.common.model.EventTimeAvroPayload;
 import org.apache.hudi.common.model.HoodieCleaningPolicy;
 import org.apache.hudi.common.model.HoodieTableType;
+import org.apache.hudi.common.model.WriteOperationType;
 import org.apache.hudi.config.HoodieIndexConfig;
 import org.apache.hudi.config.HoodieWriteConfig;
 import org.apache.hudi.exception.HoodieException;
 import org.apache.hudi.hive.MultiPartKeysValueExtractor;
+import org.apache.hudi.hive.ddl.HiveSyncMode;
 import org.apache.hudi.index.HoodieIndex;
 import org.apache.hudi.keygen.constant.KeyGeneratorOptions;
 import org.apache.hudi.keygen.constant.KeyGeneratorType;
+import org.apache.hudi.table.action.cluster.ClusteringPlanPartitionFilterMode;
 
 import org.apache.flink.configuration.ConfigOption;
 import org.apache.flink.configuration.ConfigOptions;
@@ -294,7 +297,7 @@ private FlinkOptions() {
   public static final ConfigOption<String> OPERATION = ConfigOptions
       .key("write.operation")
       .stringType()
-      .defaultValue("upsert")
+      .defaultValue(WriteOperationType.UPSERT.value())
       .withDescription("The write operation, that this write should do");
 
   /**
@@ -656,7 +659,7 @@ private FlinkOptions() {
   public static final ConfigOption<String> CLUSTERING_PLAN_PARTITION_FILTER_MODE_NAME = ConfigOptions
       .key("clustering.plan.partition.filter.mode")
       .stringType()
-      .defaultValue("NONE")
+      .defaultValue(ClusteringPlanPartitionFilterMode.NONE.name())
       .withDescription("Partition filter mode used in the creation of clustering plan. Available values are - "
           + "NONE: do not filter table partition and thus the clustering plan will include all partitions that have clustering candidate."
           + "RECENT_DAYS: keep a continuous range of partitions, worked together with configs '" + DAYBASED_LOOKBACK_PARTITIONS.key() + "' and '"
@@ -725,8 +728,8 @@ private FlinkOptions() {
   public static final ConfigOption<String> HIVE_SYNC_MODE = ConfigOptions
       .key("hive_sync.mode")
       .stringType()
-      .defaultValue("hms")
-      .withDescription("Mode to choose for Hive ops. Valid values are hms, jdbc and hiveql, default 'jdbc'");
+      .defaultValue(HiveSyncMode.HMS.name())
+      .withDescription("Mode to choose for Hive ops. Valid values are hms, jdbc and hiveql, default 'hms'");
 
   public static final ConfigOption<String> HIVE_SYNC_USERNAME = ConfigOptions
       .key("hive_sync.username")