Use the environment variable USE_GMS_LIBS to rename the library and avoid conflict with the library in GMS repo

Change-Id: I32b8b7f4dbbd5fe0825a544a482707803224a946
Handle PRODUCT_MANUFACTURER/PRODUCT_MODEL names with spaces

It's common for the PRODUCT_MODEL string to have spaces. Eg "Nexus 7"
or "AOSP on npm801".

Change-Id: I6b6f8cf2113c8264a0501497b89973c0f3825efc
Camera fixes

Initialise mClip to make sure that mClip gets allocated and free'd
correctly. Just call the CameraFaceDetector destructor directly, don't
delete the instance.

Change-Id: I590c60c56ba748d446b6ca4491309d13e66284e3
Fix SensorListener to handle case where no orientation sensor is available

Some targets do not have orientation sensor in which case there is no
need for the SensorListner to run.

Change-Id: I6d2fc14cf2a7067072d21401ef5c8b7a7dc7b19f