Error when trying to perform a single field update action using JPA-QL

I'm trying to perform an update action in a single field using gorm data services through `grails.gorm.services.Query`. In the [documentation](http://gorm.grails.org/latest/hibernate/manual/index.html#_data_service_write_operations) I found an example very similar to my case of use

```
@Query("update ${Book book} set ${book.title} = $newTitle where book.title = $oldTitle")
Number updateTitle(String newTitle, String oldTitle)
```
The code that I try is the following:

```
@Query("update ${Activity activity} set ${activity.state} = $state where activity.id = $id")
Activity updateState(final String state, final Serializable id)
```
I am getting a query exception `org.grails.orm.hibernate.exceptions.GrailsQueryException` with the following caused by message

`Invalid query [UPDATE anotherdemo.Activity as activity SET activity.state = :p0 WHERE activity.id = :p1] for domain class [anotherdemo.Activity]`

Please visit this [link](https://github.com/ilmoralito/demo-app-for-updating-single-field) to a github repository with an example app that reproduces the issue

### Environment Information

- **Operating System**: Ubuntu 16.04
- **Grails Version:** 3.3.0.M2
- **JDK Version:** Using java version 8u121

Thanks for your time

Start with the grails.gorm.services.Query data-service write-operation documentation and the linked demo app that reproduces the failure. Trace the generated update query shown in the exception; done means the single-field Activity state update executes without a GrailsQueryException and returns the expected result.

Written by the indexing model from the issue text.