Mms: Updated 'Mark as read' notification action icon

Users still think the 'Read' action means 'to read' (sounds like reed)
rather than 'the message has been read' (sounds like red).  This new
icon is an attempt to clear up the confusion and replaces the email
looking icon currenty in use by something a bit more suitable for the
Mms app.

Drawable curtesy of Björn Lundén

Screenshot:
  https://dl.dropbox.com/u/50993944/Screenshot_2013-04-08-18-16-03.png

Change-Id: I890a99c76173dfcb1179fea8ef80d24ecf5133ac

Conflicts:

	src/com/android/mms/transaction/MessagingNotification.java
Revert "Messaging: Fix the order of the Mark read action"

This reverts commit b14cbe9c7e7b5d567d084d404d5ffd9910d807b6.

Conflicts:
	src/com/android/mms/transaction/MessagingNotification.java