Depend on config rule instead of file.

The aos_config rule used to require you to depend on {name}.json to get
the output.  That was weird and hid private/testonly/etc.  Instead,
depend on the rule directly.

Change-Id: I1596a6c1f44b246a0db1bbc562468530a0b69614
diff --git a/y2018/control_loops/superstructure/BUILD b/y2018/control_loops/superstructure/BUILD
index 4e97571..db01298 100644
--- a/y2018/control_loops/superstructure/BUILD
+++ b/y2018/control_loops/superstructure/BUILD
@@ -74,7 +74,7 @@
     srcs = [
         "superstructure_lib_test.cc",
     ],
-    data = ["//y2018:config.json"],
+    data = ["//y2018:config"],
     shard_count = 5,
     deps = [
         ":superstructure_goal_fbs",