Unify source of camera geometry data

Due to parallel development, camera pose information ended up being
populated in two constants files. This makes //y2019/vision:constants
the source for all of the constants.

Also, because the camera 19 calibration was done as if it was a front
camera, I had to negate its x/y position and offset the angle by 180
degrees.

This commit also adds validation for //y2019/vision:constants.cc to
ensure that it is not accidentally changed in a way that the codegen
cannot account for.

Change-Id: I85654d973e15ae7bf76589be63c3d0eaf72c3a45
diff --git a/y2019/vision/constants.cc b/y2019/vision/constants.cc
index bc8a56d..e41a53b 100644
--- a/y2019/vision/constants.cc
+++ b/y2019/vision/constants.cc
@@ -82,9 +82,9 @@
         -0.341036 / 180.0 * M_PI, 324.626, 1.2545 / 180.0 * M_PI,
     },
     {
-        {{6.93309 * kInchesToMeters, -2.64735 * kInchesToMeters,
+        {{-6.93309 * kInchesToMeters, 2.64735 * kInchesToMeters,
           32.8758 * kInchesToMeters}},
-        2.58102 / 180.0 * M_PI,
+        -177.419 / 180.0 * M_PI,
     },
     {
         19,