fix wrong additional key.

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

@@ -56,7 +56,7 @@
       "name": "spring.cloud.polaris.event.pushgateway.enabled",
       "type": "java.lang.Boolean",
       "description": "If push gateway event reporter is enabled.",
-      "default": false
+      "defaultValue": false
     },
     {
       "name": "spring.cloud.polaris.event.pushgateway.address",
@@ -67,13 +67,13 @@
       "name": "spring.cloud.polaris.event.pushgateway.eventQueueSize",
       "type": "java.lang.Integer",
       "description": "Queue size for push gateway event queue. Default is 1000.",
-      "default": 1000
+      "defaultValue": 1000
     },
     {
       "name": "spring.cloud.polaris.event.pushgateway.maxBatchSize",
       "type": "java.lang.Integer",
       "description": "Max batch size for push gateway event. Default is 100.",
-      "default": 100
+      "defaultValue": 100
     }
   ],
   "hints": []