Switch magic timestamp channel to RemoteMessage

In order to track reboots and such, we really need to communicate more
information from the message_bridge to the logger.  It is a shame to
have to modify the MessageHeader to do this, even though it would be
nice.  Switch the remote timestamp channels over to a new RemoteMessage
channel instead, and add code to rename the channel when replaying.

There are no known log files with a MessageHeader actually logged, so
most of this should be pretty safe.  I've tested this on an old log file
by hand.

Change-Id: If81b31869b95040151d833d20ec3eb8623ab1cd4
diff --git a/aos/events/event_loop.h b/aos/events/event_loop.h
index a1f87cd..bf7381c 100644
--- a/aos/events/event_loop.h
+++ b/aos/events/event_loop.h
@@ -485,8 +485,8 @@
   template <typename T>
   bool HasChannel(const std::string_view channel_name) {
     return configuration::GetChannel(configuration(), channel_name,
-                                     T::GetFullyQualifiedName(), name(),
-                                     node()) != nullptr;
+                                     T::GetFullyQualifiedName(), name(), node(),
+                                     true) != nullptr;
   }
 
   // Note, it is supported to create: