fix: Removed FeatureDecorator class

Features that are under development will be marked as workInProgress in Javadoc for now.

PiperOrigin-RevId: 791245932

Author: google-genai-bot

core/src/main/java/com/google/adk/agents/BaseAgentConfig.java

@@ -17,10 +17,12 @@
 package com.google.adk.agents;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
-import com.google.adk.utils.FeatureDecorator.WorkInProgress;
 
-/** Base configuration for all agents. */
-@WorkInProgress
+/**
+ * Base configuration for all agents.
+ *
+ * <p>workInProgress: Config agent features are not yet ready for public use.
+ */
 public class BaseAgentConfig {
   private String name;
   private String description = "";

core/src/main/java/com/google/adk/agents/LlmAgentConfig.java

@@ -17,10 +17,12 @@
 package com.google.adk.agents;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
-import com.google.adk.utils.FeatureDecorator.WorkInProgress;
 
-/** Configuration for LlmAgent. */
-@WorkInProgress
+/**
+ * Configuration for LlmAgent.
+ *
+ * <p>workInProgress: Config agent features are not yet ready for public use.
+ */
 public class LlmAgentConfig extends BaseAgentConfig {
   private String model;
   private String instruction;