MMS: Fix can't show send or receive time

Don't include original time when merge forward messages.

If original time is not null,add it into forward content.
There are two ways to forward messages. One is from the
Compose Message's action bar menu, the other is from the
option menu. Delete the one in option menu.

CRs-Fixed: 750951

Change-Id: Ib1262e87654fbef0a559e0ff90bd5c45ec3067f5