Fix PROD_KAFKA_TOPIC_VERSION_SETTING seed value for event-manager Kafka init

Empty JSON '{}' caused event-manager TopicSettingServlet to fail during
Kafka producer initialization. Set correct format: {"events":["GCP_KAFKA"]}

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

test-framework/helm/property-settings-svc-v2/sql/002_populate_properties_table.sql

@@ -34,6 +34,6 @@ VALUES
     'AGENCY',
     'ALL',
     'PROD_KAFKA_TOPIC_VERSION_SETTING',
-    '{}',
+    '{"events":["GCP_KAFKA"]}',
     1
 );