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

### Environment

* Dubbo version: 2.6.4

### Steps to reproduce this issue

1. GenericService泛化调用
2. 使用oninvoke、onreturn、onthrow
3. FutureFilter无法正常回调

### Expected Result
StaticContext.getKey(invoker.getUrl(), invocation.getMethodName(), Constants.ON_INVOKE_METHOD_KEY)
返回
com.alibaba.boot.dubbo.demo.consumer.DemoService:1.0.0.sayHello.oninvoke.method

### Actual Result
StaticContext.getKey(invoker.getUrl(), invocation.getMethodName(), Constants.ON_INVOKE_METHOD_KEY)
返回
com.alibaba.boot.dubbo.demo.consumer.DemoService:1.0.0.$invoke.oninvoke.method

预期是：

```
        String methodName = invocation.getMethodName();
        if("$invoke".equals(methodName)) {
            Object[] arguments = invocation.getArguments();
            methodName = (String) arguments[0];
        }
```

asyncResult.thenApplyWithContext(r -> {
                asyncCallback(invoker, invocation, r);
                return r;
            });
            return asyncResult;
        } else {
            syncCallback(invoker, invocation, result);
            return result;
        }
    }
    private void syncCallback(final Invoker<?> invoker, final Invocation invocation, final Result result) {
        if (result.hasException()) {
            fireThrowCallback(invoker, invocation, result.getException());
        } else {
            fireReturnCallback(invoker, invocation, result.getValue());
        }
    }
    private void asyncCallback(final Invoker<?> invoker, final Invocation invocation, Result result) {
        if (result.hasException()) {
            fireThrowCallback(invoker, invocation, result.getException());
        } else {
            fireReturnCallback(invoker, invocation, result.getValue());
        }
    }
    private void fireInvokeCallback(final Invoker<?> invoker, final Invocation invocation) {
        final ConsumerMethodModel.AsyncMethodInfo asyncMethodInfo = getAsyncMethodInfo(invoker, invocation);
        if (asyncMethodInfo == null) {
            return;
        }
        final Method onInvokeMethod = asyncMethodInfo.getOninvokeMethod();