Add an exposure flag to y2023 Camera Reader

Signed-off-by: Ravago Jones <ravagojones@gmail.com>
Change-Id: I550887885928670a42d989d7a2d11accc9b67d25
diff --git a/y2023/vision/camera_reader.cc b/y2023/vision/camera_reader.cc
index 5949048..b604516 100644
--- a/y2023/vision/camera_reader.cc
+++ b/y2023/vision/camera_reader.cc
@@ -16,6 +16,7 @@
 DEFINE_double(red, 1.252, "Red gain");
 DEFINE_double(green, 1, "Green gain");
 DEFINE_double(blue, 1.96, "Blue gain");
+DEFINE_double(exposure, 150, "Camera exposure");
 
 namespace y2023 {
 namespace vision {
@@ -104,7 +105,7 @@
   if (FLAGS_lowlight_camera) {
     v4l2_reader.SetGainExt(100);
     v4l2_reader.SetVerticalBlanking(1000);
-    v4l2_reader.SetExposure(150);
+    v4l2_reader.SetExposure(FLAGS_exposure);
   } else {
     v4l2_reader.SetGainExt(1000);
     v4l2_reader.SetExposure(1000);