Added ByteCount to plugin parser (#4003)

Signed-off-by: Guian Gumpac <guian.gumpac@improving.com>

data-prepper-core/src/main/java/org/opensearch/dataprepper/plugin/ObjectMapperConfiguration.java

@@ -30,6 +30,7 @@ public class ObjectMapperConfiguration {
     ObjectMapper extensionPluginConfigObjectMapper() {
         final SimpleModule simpleModule = new SimpleModule();
         simpleModule.addDeserializer(Duration.class, new DataPrepperDurationDeserializer());
+        simpleModule.addDeserializer(ByteCount.class, new ByteCountDeserializer());
 
         return new ObjectMapper()
                 .setPropertyNamingStrategy(PropertyNamingStrategies.SNAKE_CASE)