Using chunk-completion-policy gives an error [BATCH-2670]

Azat opened BATCH-2670 and commented

We have the following tasklet:

<tasklet>
	<chunk reader="detail-reader"
		   writer="detail-writer"
		   commit-interval="0"
		   chunk-completion-policy="singleChunkCompletionPolicy"/>
</tasklet>

And it works fine. But the spring documentation says to use either this or chunk-completion-policy but not both.
So now if I remove commit-interval="0" it gives an error:

    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:175)
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.getObjectFromFactoryBean(FactoryBeanRegistrySupport.java:103)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getObjectForBeanInstance(AbstractBeanFactory.java:1634)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:254)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:351)
    ... 60 more
Caused by: java.lang.IllegalStateException: You must specify either a chunkCompletionPolicy or a commitInterval but not both.
    at org.springframework.util.Assert.state(Assert.java:70)
    at org.springframework.batch.core.step.builder.SimpleStepBuilder.chunk(SimpleStepBuilder.java:190)
    at org.springframework.batch.core.configuration.xml.StepParserStepFactoryBean.createFaultTolerantStep(StepParserStepFactoryBean.java:353)
    at org.springframework.batch.core.configuration.xml.StepParserStepFactoryBean.getObject(StepParserStepFactoryBean.java:274)
    at org.springframework.batch.core.configuration.xml.StepParserStepFactoryBean.getObject(StepParserStepFactoryBean.java:113)
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:168)
    ... 65 more```

Expected result:
It should let us to specify chunk-completion-policy without setting commit-interval to zero.

Affects: 3.0.7

Reproduce the XML configuration using chunk-completion-policy without commit-interval, then start at StepParserStepFactoryBean.createFaultTolerantStep and follow the call into SimpleStepBuilder.chunk. Compare how the two chunk attributes are passed to the builder. Done means the configuration is accepted with the completion policy alone and the reported IllegalStateException no longer occurs.