Add ids to flatbuffer fields in y2012, y2016, frc971, and aos

Change-Id: I9ed9006ce6224e2df0459df47771786b928164a1
diff --git a/frc971/autonomous/auto_mode.fbs b/frc971/autonomous/auto_mode.fbs
index 412cd17..b6bff20 100644
--- a/frc971/autonomous/auto_mode.fbs
+++ b/frc971/autonomous/auto_mode.fbs
@@ -2,7 +2,7 @@
 
 table AutonomousMode {
   // Mode read from the mode setting sensors.
-  mode:int;
+  mode:int (id: 0);
 }
 
 root_type AutonomousMode;