Update recommended Java artifact version.
Update recommended Java artifact version.

googleapis/google-cloud-datastore,eddavisson/google-cloud-datastore,pcostell/google-cloud-datastore,pcostell/google-cloud-datastore,googleapis/google-cloud-datastore,googleapis/google-cloud-datastore,eddavisson/google-cloud-datastore,eddavisson/google-cloud-datastore,pcostell/google-cloud-datastore,eddavisson/google-cloud-datastore,pcostell/google-cloud-datastore