Should be able to set empty directory flag to TRUE in DynamoDBMetadataStore#innerGet when using authoritative directory listings

        // When this class has support for authoritative
        // (fully-cached) directory listings, we may also be able to answer
        // TRUE here.  Until then, we don't know if we have full listing or
        // not, thus the UNKNOWN here:
        meta.setIsEmptyDirectory(
            hasChildren ? Tristate.FALSE : Tristate.UNKNOWN);