[BUG] App not releasing the camera onPause()

[lolobosse]

Requirements:
Device: Nexus 4
SDK: 22

Steps to reproduce:

• Open the sample and open the camera.
• Let the preview run and switch to another camera app with multitask button

Current Behaviour:

• The other app cannot connect to the camera because this lib didn't free the access to it.

Expected behaviour:

• The other app should be able to connect to the camera