Update examples/customer-behavior/main.bal

Co-authored-by: Ayesh Almeida <77491511+ayeshLK@users.noreply.github.com>

examples/customer-behavior/main.bal

@@ -30,7 +30,7 @@ hsproperties:OAuth2RefreshTokenGrantConfig auth = {
 };
 final hsproperties:Client hubSpotProperties = check new ({ auth });
 
-string groupName = "customer_behavior";
+const GROUP_NAME = "customer_behavior";
 string customPropertyName = "purchase_frequency_property";
 string dependantPropertyName = "preferred_channel_property";