fix: Increase max output tokens for Claude to 8k

PiperOrigin-RevId: 786499934

Author: shukladivyansh

core/src/main/java/com/google/adk/models/Claude.java

@@ -60,7 +60,7 @@
 public class Claude extends BaseLlm {
 
   private static final Logger logger = LoggerFactory.getLogger(Claude.class);
-  private static final int MAX_TOKEN = 1024;
+  private static final int MAX_TOKEN = 8192;
   private final AnthropicClient anthropicClient;
 
   /**