* This fixes the case in which messages are being loaded upon
initial sync, but do NOT appear in the message list (at least
until leaving and re-entering the app/mailbox)
* The problem was that MessagesAdapter was checking the state
of the HOLDS_MAIL flag, which might not have been set at the
time the Inbox was created; it turns out that the check is
not necessary, so we remove it here
Bug: 5008696
Change-Id: I009ddf7d82d938758b99c855dfd0271596c5248a
4c0e5c0d0a