Javadoc
Create a UnitAllocation according to the given actionDescriptionBuilder.
The resourceAllocation and the executionTimePeriod inside the actionDescription have to be initialized. The executionTimePeriod is used for the completionType of the internal ExecutableResource.
Zero results in the completionType EXPIRE which will free the resource directly after onAllocation finished. Everything else will result in RETAIN which will
block the resource until the slot defined in the ResourceAllocation expires.