Fixed native camera support in Android.mk

OpenCV.mk.in

@@ -14,8 +14,12 @@ OPENCV_MODULES := contrib calib3d objdetect features2d imgproc video  highgui ml
 ifeq ($(TARGET_ARCH_ABI),armeabi)
 OPENCV_CAMERA_MODULES:=
 else
+ifeq (${OPENCV_CAMERA_MODULES},off)
+OPENCV_CAMERA_MODULES:=
+else
 OPENCV_CAMERA_MODULES:=@CMAKE_CAMERA_LIBS_CONFIGCMAKE@
 endif
+endif
 
 OPENCV_LIB_TYPE:=@OPENCV_LIBTYPE_CONFIGMAKE@