Addressed comments

Author: allenkim0129

sdk/cosmos/azure-cosmos-tests/src/test/java/com/azure/cosmos/rx/VectorIndexTest.java

@@ -341,22 +341,22 @@ private List<CosmosVectorIndexSpec> populateVectorIndexes() {
         CosmosVectorIndexSpec cosmosVectorIndexSpec2 = new CosmosVectorIndexSpec()
             .setPath("/vector2")
             .setType(CosmosVectorIndexType.QUANTIZED_FLAT.toString())
-            .setQuantizerType(QuantizerType.product)
+            .setQuantizerType(QuantizerType.PRODUCT)
             .setQuantizationSizeInBytes(2)
             .setVectorIndexShardKeys(Arrays.asList("/zipCode"));
 
         CosmosVectorIndexSpec cosmosVectorIndexSpec3 = new CosmosVectorIndexSpec()
             .setPath("/vector3")
             .setType(CosmosVectorIndexType.DISK_ANN.toString())
-            .setQuantizerType(QuantizerType.product)
+            .setQuantizerType(QuantizerType.PRODUCT)
             .setQuantizationSizeInBytes(2)
             .setIndexingSearchListSize(30)
             .setVectorIndexShardKeys(Arrays.asList("/country/city"));
 
         CosmosVectorIndexSpec cosmosVectorIndexSpec4 = new CosmosVectorIndexSpec()
             .setPath("/vector4")
             .setType(CosmosVectorIndexType.DISK_ANN.toString())
-            .setQuantizerType(QuantizerType.spherical)
+            .setQuantizerType(QuantizerType.SPHERICAL)
             .setIndexingSearchListSize(30)
             .setVectorIndexShardKeys(Arrays.asList("/country/city"));
 

sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/Constants.java

@@ -3,7 +3,6 @@
 
 package com.azure.cosmos.implementation;
 
-import java.util.List;
 
 /**
  * Used internally. Constants in the Azure Cosmos DB database service Java SDK.
@@ -121,7 +120,7 @@ public static final class Properties {
         public static final String ORDER = "order";
         public static final String SPATIAL_INDEXES = "spatialIndexes";
         public static final String TYPES = "types";
-        public static final String QUANTIZER_TYPE = "QuantizerType";
+        public static final String QUANTIZER_TYPE = "quantizerType";
 
         // Full text search
         public static final String FULL_TEXT_INDEXES = "fullTextIndexes";

sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/models/CosmosVectorIndexSpec.java

@@ -87,7 +87,7 @@ public CosmosVectorIndexSpec setType(String type) {
     }
 
     /**
-     * Gets quantizer type.
+     * Gets the quantizer type.
      *
      * @return the quantizer type.
      */
@@ -99,17 +99,18 @@ public QuantizerType getQuantizerType() {
     }
 
     /**
-     * Set quantizer type.
+     * Set the quantizer type.
      *
      * @param quantizerType The quantizer type
-     * @return the SpatialSpec.
+     * @return the CosmosVectorIndexSpec.
      */
     public CosmosVectorIndexSpec setQuantizerType(QuantizerType quantizerType) {
         if (validateIndexType(IndexProperty.QUANTIZER_TYPE) && quantizerType != null) {
             this.quantizerType = quantizerType;
             this.jsonSerializable.set(Constants.Properties.QUANTIZER_TYPE, quantizerType);
         } else {
             this.quantizerType = null;
+            this.jsonSerializable.remove(Constants.Properties.QUANTIZER_TYPE);
         }
         return this;
     }

sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/models/QuantizerType.java

@@ -3,19 +3,21 @@
 
 package com.azure.cosmos.models;
 
+import com.fasterxml.jackson.annotation.JsonValue;
+
 /**
- * Defines the quantizer type of vector index path specification in the Azure Cosmos DB service.
+ * Defines quantizer types for vector index specifications in the Azure Cosmos DB service.
  */
 public enum QuantizerType {
     /**
-     * Represent a product quantizer type.
+     * Represents a product quantizer type.
      */
-    product("product"),
+    PRODUCT("product"),
 
     /**
-     * Represent a spherical quantizer type.
+     * Represents a spherical quantizer type.
      */
-    spherical("spherical");
+    SPHERICAL("spherical");
 
 
     QuantizerType(String overWireValue) {
@@ -24,6 +26,7 @@ public enum QuantizerType {
 
     private final String overWireValue;
 
+    @JsonValue
     @Override
     public String toString() {
         return this.overWireValue;