Add camera recording hint parameter.

The API is still hidden.

bug:4266229
Change-Id: I5e4c24e9e2808582aecb55ac4f1d5be3ed7e36a2
diff --git a/camera/CameraParameters.cpp b/camera/CameraParameters.cpp
index d8fef09..251615d 100644
--- a/camera/CameraParameters.cpp
+++ b/camera/CameraParameters.cpp
@@ -86,6 +86,7 @@
 const char CameraParameters::KEY_PREFERRED_PREVIEW_SIZE_FOR_VIDEO[] = "preferred-preview-size-for-video";
 const char CameraParameters::KEY_MAX_NUM_DETECTED_FACES_HW[] = "max-num-detected-faces-hw";
 const char CameraParameters::KEY_MAX_NUM_DETECTED_FACES_SW[] = "max-num-detected-faces-sw";
+const char CameraParameters::KEY_RECORDING_HINT[] = "recording-hint";
 
 const char CameraParameters::TRUE[] = "true";
 const char CameraParameters::FALSE[] = "false";