Create enable MMS notification.

Adding a notification in SimSelectNotification that will be triggered
when receiving a enable MMS request. Tapping on the notificaiton will
lead to the subscription setting page.

Bug: 130222866
Test: manual -- have a test app that sends the intent when mobile
data is turned off. And verify that the heads-up notificaiton is shown
and that it will lead to subscription setting page.

Change-Id: Ia80e8e5ab20adf78a31647a23cb2ba8dac690e41