ET集成Seata AT模式时，EtDataSourceManager类获取不到DataSourceProxy

[hiiloveyou]

Describe the bug

//ET要求使用Spring管控下的事务，因此本方法可以获得对应的当前连接,获取当前连接来执行时为了避免争夺连接词的连接导致死锁
        DataSourceProxy dataSourceProxy = get(resourceId);
        ConnectionProxy cp = (ConnectionProxy) DataSourceUtils.getConnection(dataSourceProxy);
        Connection targetConnection = cp.getTargetConnection();

EtDataSourceManager类代码79行，DataSourceProxy dataSourceProxy = get(resourceId); dataSourceProxy为null

EtDataSourceManager的静态方法初始化时没有把 DataSourceProxy注册到EtDataSourceManager

 public static void initEtDataSourceManager() {
        DefaultResourceManager.get();
        DefaultResourceManager.mockResourceManager(BranchType.AT, new EtDataSourceManager());
        LOGGER.info("Trigger EtSeataDataSourceManager init!");
    }

由于使用了DefaultResourceManager.mockResourceManager(BranchType.AT, new EtDataSourceManager());，因此 EtDataSourceManager从父类的dataSourceCache获取DataSourceProxy时为空.

应该需要将DataSourceProxy资源再次注入到EtDataSourceManager。我试着改为如下方式可用

public static void initEtDataSourceManager() {
        final Map<String, Resource> resourceMap = DefaultResourceManager.get().getResourceManager(BranchType.AT).getManagedResources();
        DefaultResourceManager.mockResourceManager(BranchType.AT, new EtDataSourceManager());
        for (Map.Entry<String, Resource> entry : resourceMap.entrySet()) {
            DefaultResourceManager.get().registerResource(entry.getValue());
        }

        LOGGER.info("Trigger EtSeataDataSourceManager init!");
    }

我看issue之前有人提出过这个问题，希望能得到解决