enable camera support without openCV manager
http://stackoverflow.com/questions/12615712/static-initialization-on-opencv-android
http://docs.opencv.org/trunk/doc/tutorials/introduction/android_binary_package/dev_with_OCV_on_Android.html#application-development-with-static-initialization

adb push the following .so to device's /system/lib
lib/armeabi-v7a/libopencv_java.so
lib/armeabi-v7a/libnative_camera_r4.2.0.so
lib/armeabi-v7a/libopencv_info.so