Lesson activity always shows "Incomplete" or 0% score when using "Incomplete/Complete" scale.

Steps to Reproduce:

1. Create a lesson assignment; taking all defaults
2. Add a page or two, making sure at least one is graded (essay or true/false question type, for example).
3. Take the lesson as a student
4. Grade the lesson, giving either a grade of "Complete" or "1", depending on whether or not custom grading used.
5. Note that while the "Reports" tab shows 100%, the gradebook will show "Incomplete" or "0%".

Actual Results: No matter what the student actual score, it always shows up as "incomplete" in the gradebook when using the "Incomplete/Complete" scale for a Lesson assignment.

Expected Results: A score of "complete" or 100% should show up as "Complete" in the gradebook when using the "Incomplete/Complete" scale for a Lesson assignment

Tested whether or not "custom scoring" has anything to do with the behavior, it does not. I added a standard Assignment to make sure a 100% score should appear as "Complete" in the gradebook, it does.