CameraService: fix race condition and wrong last frame number.

Change-Id: Ie2be9a77a0b074497615de38cbb8e8f13b4858ec
diff --git a/include/camera/camera2/ICameraDeviceUser.h b/include/camera/camera2/ICameraDeviceUser.h
index 49daf69..913696f 100644
--- a/include/camera/camera2/ICameraDeviceUser.h
+++ b/include/camera/camera2/ICameraDeviceUser.h
@@ -31,6 +31,10 @@
 class CaptureRequest;
 class CameraMetadata;
 
+enum {
+    NO_IN_FLIGHT_REPEATING_FRAMES = -1,
+};
+
 class ICameraDeviceUser : public IInterface
 {
     /**