Do copy apps for the exchange

P2 bugfix
http://manage.dimagi.com/default.asp?151558
Reverts behavior introduced [here](https://github.com/dimagi/commcare-hq/commit/b03a251?w=1) which was causing projects to appear on the exchange without apps.  This only happened sometimes - it appeared to be only when the apps in question were having the latest starred build published.
@emord FYI

This was a bit tricky to track down, and I found a couple [red herrings](https://github.com/dimagi/commcare-hq/pull/5160) on the trail.  I think the intent of the original change is good, but not sure how best to implement it, so I figure this revert should be a simple-enough fix.