feat:update examples

spring-cloud-tencent-examples/polaris-discovery-example/discovery-caller-service/src/main/java/com/tencent/cloud/polaris/discovery/service/caller/DiscoveryCalleeService.java

@@ -24,7 +24,7 @@ import org.springframework.web.bind.annotation.RequestParam;
 /**
  * @author Haotian Zhang
  */
-@FeignClient("DiscoveryCalleeService")
+@FeignClient(value = "DiscoveryCalleeService", fallback = DiscoveryCalleeServiceCallback.class)
 public interface DiscoveryCalleeService {
 
     /**

spring-cloud-tencent-starters/spring-cloud-starter-tencent-polaris-discovery/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -6,6 +6,12 @@
       "defaultValue": "${spring.application.name}",
       "description": "the service name to register, default value is ${spring.application.name}."
     },
+    {
+      "name": "spring.cloud.polaris.discovery.namespace",
+      "type": "java.lang.String",
+      "defaultValue": "default",
+      "description": "the namespace of service, default value is ${spring.application.name}."
+    },
     {
       "name": "spring.cloud.polaris.discovery.enabled",
       "type": "java.lang.Boolean",