Fixing notification format for multirecipient notifications

Bug:1373917 internal notifications were displayed fine, but for external
notifications, the notification text needed to be formatted using
format_notification_whitespace

Change-Id: Ia97efb2c18a8091b2abbccacf278868a19b8e96a
Signed-off-by: Tobias Zeuch <tobias.zeuch@kit.edu>