Performance issue in NurseRostering example

We had a major decrease in the score calculation of 

NurseRostering problem due to moving to constraint streams. To deal with it we introduced feature here https://issues.redhat.com/browse/BAPL-1987

However we were needed to update the example in order to use it properly: as it was made in this PR https://github.com/kiegroup/optaplanner/commit/d3387a1452bc9fe7aa66ce3fb70c3e36adc8bc36

Seems like we didnt cherry pick it to 8.11.x so it didnt get to product 7.12