b/10413188
There are still several issues with attachments generally,
but this fixes the most glaring problem: We were short circuiting
in a loop that needed to populate a hash table of remote message
Ids, so not all of them would be present. The later code intended
to load attachments expected it to be fully populated.
There are still several problems, notably that if downloading
doesn't work, it just spins forever, but this fixes the first
problem.
Change-Id: I2b23dcb841edabe108096933fea2350ef61a10f1
85ff07a00a