Move uuid to //aos:uuid

It is getting usage significantly further outside the logger.  Time to
promote it somewhere better.  I only see it getting used more.

Change-Id: I754739347212f5a3154f68c7b7fc84b9a9074d90
diff --git a/aos/events/logging/log_reader.cc b/aos/events/logging/log_reader.cc
index 881f9c1..07b423f 100644
--- a/aos/events/logging/log_reader.cc
+++ b/aos/events/logging/log_reader.cc
@@ -13,7 +13,6 @@
 #include "aos/events/event_loop.h"
 #include "aos/events/logging/logfile_sorting.h"
 #include "aos/events/logging/logger_generated.h"
-#include "aos/events/logging/uuid.h"
 #include "aos/flatbuffer_merge.h"
 #include "aos/network/multinode_timestamp_filter.h"
 #include "aos/network/remote_message_generated.h"
@@ -22,6 +21,7 @@
 #include "aos/network/timestamp_channel.h"
 #include "aos/time/time.h"
 #include "aos/util/file.h"
+#include "aos/uuid.h"
 #include "flatbuffers/flatbuffers.h"
 #include "openssl/sha.h"