[Android] Add condition to avoid duplecated intents receiver registration.

The registration existed in both constructor and onActivityStateChange()
method for MessagingSmsManager, so add a switch to avoid duplecated
registration.

BUG=https://crosswalk-project.org/jira/browse/XWALK-2614
(cherry picked from commit 6b4e9ac44aed4c905a5ddb8556fe8e6f9a7e4abf)