b/13349278. Fix multiple downloads of the same attachment.

The problem was due to a different set of error codes being used
internally within the EasLoadAttachment class and the externally
used EmailServiceStatus codes.  The fix was to be consistent about
using interal codes only internally and using the EmailServiceStatus
codes when pushing status (via callbacks) back to the
AttachmentDownload service.

Change-Id: I8b7705384c156d8e4a814059bb7b2ecbbb57d574
(cherry picked from commit dd5d8689a7beb735b061361caf3aefa6d7675bf9)
1 file changed