Add YV12 preview format to camera parameter constants.

bug:3463624
Change-Id: I8f2992dadfd3fb9e3c9d67743e52da7f3212827e
diff --git a/include/camera/CameraParameters.h b/include/camera/CameraParameters.h
index 431aaa4..da2f049 100644
--- a/include/camera/CameraParameters.h
+++ b/include/camera/CameraParameters.h
@@ -417,11 +417,10 @@
 
     // Pixel color formats for KEY_PREVIEW_FORMAT, KEY_PICTURE_FORMAT,
     // and KEY_VIDEO_FRAME_FORMAT
-    // Planar variant of the YUV420 color format
-    static const char PIXEL_FORMAT_YUV420P[];
     static const char PIXEL_FORMAT_YUV422SP[];
     static const char PIXEL_FORMAT_YUV420SP[]; // NV21
     static const char PIXEL_FORMAT_YUV422I[]; // YUY2
+    static const char PIXEL_FORMAT_YUV420P[]; // YV12
     static const char PIXEL_FORMAT_RGB565[];
     static const char PIXEL_FORMAT_JPEG[];