Move array_vector.

Once refactor is complete, it will only be used by metadata.

Change-Id: Ie1e203f558f2f9a12c3be949d98454341648ee9d
diff --git a/modules/camera/3_4/v4l2_camera.h b/modules/camera/3_4/v4l2_camera.h
index 2638993..17770b6 100644
--- a/modules/camera/3_4/v4l2_camera.h
+++ b/modules/camera/3_4/v4l2_camera.h
@@ -25,9 +25,9 @@
 
 #include <system/camera_metadata.h>
 
-#include "array_vector.h"
 #include "camera.h"
 #include "common.h"
+#include "metadata/array_vector.h"
 #include "v4l2_gralloc.h"
 #include "v4l2_wrapper.h"