Nest all namespaces

The compiler supports this now.  We can type less going forward.
No functional changes.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I29d6fa4f9aacc0e381f1a7637294db0392466995
diff --git a/aos/starter/starter_rpc_lib.cc b/aos/starter/starter_rpc_lib.cc
index 4e9ceef..891355e 100644
--- a/aos/starter/starter_rpc_lib.cc
+++ b/aos/starter/starter_rpc_lib.cc
@@ -6,8 +6,7 @@
 #include "aos/flatbuffer_merge.h"
 #include "aos/starter/starterd_lib.h"
 
-namespace aos {
-namespace starter {
+namespace aos::starter {
 
 namespace {
 State ExpectedStateForCommand(Command command) {
@@ -307,5 +306,4 @@
                    status_fetcher.CopyFlatBuffer()));
 }
 
-}  // namespace starter
-}  // namespace aos
+}  // namespace aos::starter