* The comment threads are formed after processing the comments in a
sorted order by timestamp and moving all drafts to the end. Each comment
is checked to see if it can be attached to an existing thread or not.
If not, then a new comment thread is formed.
The current sorting method had a bug where the drafts would not move to
the end of the array. This change fixes that bug.
Change-Id: I882cf804cee10b1713798da5dc130acfa68fa773
b84bf91c22