[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
Merge pull request #2456 from gaochun/2614

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