2.7.7.1 ignores comprehension performance in promotion decisions

[JackMostow]

RoboTutor/app/src/main/java/cmu/xprize/robotutor/tutorengine/util/PerformancePromotionRules.java lists all story.* activities as nonassessable -- even cloze and picture-matching comprehension. I.e. even if it scores the attempts as successful or not, it promotes to NEXT regardless of % correct.
It might still require > 2 attempts, but what counts as an attempt in story -- a word? a sentence? a question?