Mms: update new messages notification count

Mms should notify the system about how many new sms/mms has (including those ones under conversations)
to the notification system. This allow the system to display the number of events for Mms app according its
settings

Change-Id: I15953283ae657b770869f611a886452199550d67
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>
Mms: remove unnecesary reference to xxhdpi/ic_menu_call.png

ic_menu_call.png is not used anymore and is caused crashed on low resolution devices

Change-Id: Iaafeed7c467cd128908b20361752d20b218c0f40
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>