Rename shell namespace to service_manager

mash/catalog_viewer/main.cc

Index: mash/catalog_viewer/main.cc
diff --git a/mash/catalog_viewer/main.cc b/mash/catalog_viewer/main.cc
index 7a2c0a7d49f5898db8866828b92f70af9277f5c1..620af243cb5ee72f3d4d435bebf7d81f7c44d069 100644
--- a/mash/catalog_viewer/main.cc
+++ b/mash/catalog_viewer/main.cc
@@ -7,6 +7,7 @@
 #include "services/service_manager/public/cpp/service_runner.h"
 
 MojoResult ServiceMain(MojoHandle service_request_handle) {
-  shell::ServiceRunner runner(new mash::catalog_viewer::CatalogViewer);
+  service_manager::ServiceRunner runner(
+      new mash::catalog_viewer::CatalogViewer);
   return runner.Run(service_request_handle);
 }