Rename config.json to aos_config.json

Plenty of other things are called config.json, so let's pick a more
unique name.

Change-Id: I6510a172ec62674dd1b11bd71cef9aac2480c612
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/y2020/vision/extrinsics_calibration.cc b/y2020/vision/extrinsics_calibration.cc
index f2ac926..5f08527 100644
--- a/y2020/vision/extrinsics_calibration.cc
+++ b/y2020/vision/extrinsics_calibration.cc
@@ -20,7 +20,7 @@
 #include "y2020/vision/sift/sift_training_generated.h"
 #include "y2020/vision/tools/python_code/sift_training_data.h"
 
-DEFINE_string(config, "config.json", "Path to the config file to use.");
+DEFINE_string(config, "aos_config.json", "Path to the config file to use.");
 DEFINE_string(pi, "pi-7971-2", "Pi name to calibrate.");
 DEFINE_bool(plot, false, "Whether to plot the resulting data.");