Merge pull request #9276 from ssaroha/sms-notification-bug837029

Bug 837029 - [SMS] - Fix for SMS app attempts to show deleted sms from new message notification r=julienw(cherry picked from commit 23f0b698f96affd9242382178202bedb14bc91ad)
Bug 837029 - Text Change in the alert shown on deleted SMS if new message notification still exists r=julien
(cherry picked from commit c79b70526e676c880b4bbd293b97bb20a0e9eeb2)