refactor: update MessageChatMemoryAdvisor instantiation to use builder pattern

Replace direct constructor usage with builder pattern for MessageChatMemoryAdvisor across multiple examples:
- ReflectionAgent in agents/reflection
- Application in model-context-protocol/sqlite/chatbot
- Application in model-context-protocol/web-search/brave-chatbot

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>

agents/reflection/src/main/java/org/springframework/ai/openai/samples/helloworld/ReflectionAgent.java

@@ -36,7 +36,7 @@ public class ReflectionAgent {
                         Your task is to Generate the best content possible for the user's request. If the user provides critique,
                         respond with a revised version of your previous attempt.
                         """)
-                .defaultAdvisors(new MessageChatMemoryAdvisor(MessageWindowChatMemory.builder().build()))
+                .defaultAdvisors(MessageChatMemoryAdvisor.builder(MessageWindowChatMemory.builder().build()).build())
                 .build();
 
         this.critiqueChatClient = ChatClient.builder(chatModel)
@@ -45,7 +45,7 @@ public class ReflectionAgent {
                         If the user content has something wrong or something to be improved, output a list of recommendations
                         and critiques. If the user content is ok and there's nothing to change, output this: <OK>
                         """)
-                .defaultAdvisors(new MessageChatMemoryAdvisor(MessageWindowChatMemory.builder().build()))
+                .defaultAdvisors(MessageChatMemoryAdvisor.builder(MessageWindowChatMemory.builder().build()).build())
                 .build();
     }
 

model-context-protocol/sqlite/chatbot/src/main/java/org/springframework/ai/mcp/samples/sqlite/Application.java

@@ -35,7 +35,7 @@ public class Application {
 
 			var chatClient = chatClientBuilder
 					.defaultToolCallbacks(new SyncMcpToolCallbackProvider(mcpClients))
-					.defaultAdvisors(new MessageChatMemoryAdvisor(MessageWindowChatMemory.builder().build()))
+					.defaultAdvisors(MessageChatMemoryAdvisor.builder(MessageWindowChatMemory.builder().build()).build())
 					.build();
 
 			var scanner = new Scanner(System.in);

model-context-protocol/web-search/brave-chatbot/src/main/java/org/springframework/ai/mcp/samples/brave/Application.java

@@ -29,7 +29,7 @@ public class Application {
 			var chatClient = chatClientBuilder
 					.defaultSystem("You are useful assistant and can perform web searches Brave's search API to reply to your questions.")
 					.defaultToolCallbacks(new SyncMcpToolCallbackProvider(mcpSyncClients))
-					.defaultAdvisors(new MessageChatMemoryAdvisor(MessageWindowChatMemory.builder().build()))
+					.defaultAdvisors(MessageChatMemoryAdvisor.builder(MessageWindowChatMemory.builder().build()).build())
 					.build();
 
 			// Start the chat loop