Improve plugin compatibility

The plugin was working well on device with recent versions of android, but was failing on older ones.
So we added a conditional statement to handle it.

Feel free to ask if you need any further information.

As we need to have this modification available on phonegap build platform, could you plan to integrate it ?
Or do you prefer us to create a new one ?

Thanks in advance

Blitzr Team
http://blitzr.com