Mms: set notification number attribute for messages

This will enable also the notification count overlay properly

PS2: remove tabs
PS3: chain notification builder calls

Change-Id: Ib127a23b0fd6f4f038eaf2553392fa2c48c9f6e8
Signed-off-by: maxwen <max.weninger@gmail.com>
Merge "Mms: set notification number attribute for messages" into jb-mr1