Spring Cloud Config Database Backend - Cannot resolve property

I have a requirement to store and consume configurations via PostgreSQL DB.I have entered following queries to the DB

CREATE TABLE xlabs.properties (  application varchar(200) DEFAULT NULL,  profile varchar(200) DEFAULT NULL,  label varchar(200) DEFAULT NULL,  prop_key  varchar(500) DEFAULT NULL,  value varchar(500) DEFAULT NULL,  id SERIAL PRIMARY KEY);INSERT INTO xlabs.properties (application, profile, label, prop_key, value) VALUES ('config-server','development','latest','ssn','([0-9]{9})');

So, After running config server and hit on http://localhost:8090/config-server/development/latest will return this response.

{"name":"config-server","profiles":["development"],"label":"latest","version":null,"state":null,"propertySources":[{"name":"config-server-development","source":{"ssn":"([0-9]{9})"}}]}

But the problem is when I try to consume above ssn property through cloud config client with following configurations, in bootstrap.properties

spring.cloud.config.uri=http://localhost:8090spring.profiles.active=developmentmanagement.endpoints.web.exposure.include=*spring.application.name=config-serverspring.cloud.config.label=latest

and

@RestController@RefreshScopepublic class ConfigController {    @Value("${ssn}")    private String name;    @GetMapping("/message")    public String returnConfig(){        return this.name;    }}

So, When I run the project it gives run time error

Could not resolve placeholder 'ssn' in value "${ssn}"

Please help on this.