混合使用注解和XML配置导致出现两个application实例（Mixing annotations and XML configuration results in two instances of application）

### Environment

* Dubbo version: 2.7.16
* Operating System version: Window 10
* Java version: 1.8

### Steps to reproduce this issue
我并没有使用3.0以上版本，因为和其他的组件兼容性还不够好（I didn't use version 3.0 or above because the compatibility with other components was not good enough）
1. 我使用@EnableDubbo和@DubboReference注解注入我需要的Spring bean，dubbo的application 和registry信息使用XML 配置，并使用@ImportResource加载此XML配置（I inject Spring beans using @EnableDubbo and @DubboReference, the application and registry information is configured using XML, and I use @ImportResource to load this XML configuration）
2. 在运行项目后出现此错误（I got this error after running the project）：org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'org.apache.dubbo.config.ApplicationConfig' available: expected single matching bean but found 2: demo-consumer,org.apache.dubbo.config.ApplicationConfig#0
3. 出现了两个application实例（There are two application instances）

我给出实现上述错误的案例代码配置（I give the configuration of the case code that achieves the above error:）：

`
@EnableDubbo
@SpringBootApplication
@ImportResource(value = "classpath:spring/dubbo-demo-consumer.xml")
public class ConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(ConsumerApplication.class, args);
}
}
`

`

`

`@RestController
public class TestController {
@DubboReference
private DemoService demoService;
}`