Put remote boot UUID in ServerStatistics and RemoteMessage

This makes it so we can see when a remote reboots easily, and gives us a
stepping stone to putting it in the log file header.

RemoteMessage then goes to the logger, so we are ready to teach the
logger how to detect and handle reboots.

Change-Id: I943de46094b60535c92a677b430d6828933b820d
diff --git a/aos/network/message_bridge_protocol.cc b/aos/network/message_bridge_protocol.cc
index 8936da8..53102c2 100644
--- a/aos/network/message_bridge_protocol.cc
+++ b/aos/network/message_bridge_protocol.cc
@@ -13,12 +13,15 @@
 
 aos::FlatbufferDetachedBuffer<aos::message_bridge::Connect> MakeConnectMessage(
     const Configuration *config, const Node *my_node,
-    std::string_view remote_name) {
+    std::string_view remote_name, std::string_view boot_uuid) {
   CHECK(config->has_nodes()) << ": Config must have nodes to transfer.";
 
   flatbuffers::FlatBufferBuilder fbb;
   fbb.ForceDefaults(true);
 
+  flatbuffers::Offset<flatbuffers::String> boot_uuid_offset =
+      fbb.CreateString(boot_uuid);
+
   flatbuffers::Offset<Node> node_offset =
       RecursiveCopyFlatBuffer<Node>(my_node, &fbb);
   const std::string_view node_name = my_node->name()->string_view();
@@ -46,6 +49,7 @@
   Connect::Builder connect_builder(fbb);
   connect_builder.add_channels_to_transfer(channels_offset);
   connect_builder.add_node(node_offset);
+  connect_builder.add_boot_uuid(boot_uuid_offset);
   fbb.Finish(connect_builder.Finish());
 
   return fbb.Release();