Mms: Avoid showing a window when marking as read

Change the "mark as read" action implementation, so that it
uses a BroadcastReceiver instead of an Activity.

The downside of using an Activity is that the current top
activity will be paused and resumed. This pausing, however
brief, may disturb what the user is doing, like watching a
kitty video on youtube.

Change-Id: I1fe3868a1e82856e42265b14590fab721492db59
Mms auto-retrieval (3/3): mms app

Change-Id: I32b6d46aa43d3cb96125d8a8264f3fc9e6d3f18c

It's only porting this http://review.cyanogenmod.org/#/c/26167/
Part 3 of 3