Respect WasReset() indicator in the drivetrain

At least, pay attention to it for the localizer/down estimator.

Change-Id: I9cf8720c7ad9b2bd1f16b8e65acf824b10f3c7ed
diff --git a/aos/events/simulated_event_loop.cc b/aos/events/simulated_event_loop.cc
index c429eef..2eaffa0 100644
--- a/aos/events/simulated_event_loop.cc
+++ b/aos/events/simulated_event_loop.cc
@@ -346,7 +346,9 @@
       return std::make_pair(false, monotonic_clock::min_time);
     }
 
-    CHECK(!fell_behind_) << ": Got behind";
+    CHECK(!fell_behind_) << ": Got behind on "
+                         << configuration::StrippedChannelToString(
+                                simulated_channel_->channel());
 
     SetMsg(msgs_.front());
     msgs_.pop_front();