- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.
- [x] I have checked the [FAQ](https://github.com/apache/dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 2.7.3
* Operating System version: Mac OS
* Java version: 1.8

### Steps to reproduce this issue

1.RouterChain#buildChain(URL)
2.RouterChain#initWithRouters()
3.RouterChain#sort()


### Expected Result

ServiceRouter is High priority than AppRouter

### Actual Result

AppRouter is High priority than ServiceRouter

### Cause by
the code was on ListenableRouter 94~96 line
```
public abstract class ListenableRouter extends AbstractRouter implements ConfigurationListener {    
    ......
    ......
    @Override
    public int getPriority() {
        return DEFAULT_PRIORITY;
    }
```
### Resolve
i think can like this：
```
public abstract class ListenableRouter extends AbstractRouter implements ConfigurationListener {    
    ......
    ......
    @Override
    public int getPriority() {
        return priority;
    }
```
return DEFAULT_PRIORITY;
    }
    @Override
    public boolean isForce() {
        return (routerRule != null && routerRule.isForce());
    }
    private boolean isRuleRuntime() {
        return routerRule != null && routerRule.isValid() && routerRule.isRuntime();
    }
    private void generateConditions(ConditionRouterRule rule) {
        if (rule != null && rule.isValid()) {
            this.conditionRouters = rule.getConditions()
                    .stream()
                    .map(condition -> new ConditionRouter(condition, rule.isForce(), rule.isEnabled()))
                    .collect(Collectors.toList());
        }
    }
    private synchronized void init(String ruleKey) {
        if (StringUtils.isEmpty(ruleKey)) {
            return;
        }
        String routerKey = ruleKey + RULE_SUFFIX;
        ruleRepository.addListener(routerKey, this);
        String rule = ruleRepository.getRule(routerKey, DynamicConfiguration.DEFAULT_GROUP);
        if (StringUtils.isNotEmpty(rule)) {
            this.process(new ConfigChangedEvent(routerKey, DynamicConfiguration.DEFAULT_GROUP, rule));
        }
    }
}