Rename shell namespace to service_manager

services/service_manager/manifest.json

 {
   "manifest_version": 1,
   "name": "service:shell",
   "display_name": "Service Manager",
   "capabilities": {
     // NOTE: This manifest is for documentation purposes only. Relevant
     // capability spec is defined inline in the ServiceManager implementation.
     //
     // TODO(rockot): Fix this. We can bake this file into ServiceManager at
     // build time or something. Same with service:catalog.
     "provided": {
       // Clients requesting this class are able to connect to other clients as
       // specific users other than their own.
       "shell:user_id": [ ],
       // Clients requesting this class are allowed to register clients for
       // processes they launch themselves.
       "shell:client_process": [ ],
       // Clients requesting this class are allowed to connect to other clients
       // in specific process instance groups.
       "shell:instance_name": [ ],
       // Clients requesting this class are run as a unique user id which is
       // visible to clients run as any user.
       "shell:all_users": [ ],
       "shell:block_wildcard":  [ ],
       // Clients requesting this class block inbound requests to bind interfaces
       // from other sources who specify wildcard rules in their manifest
       // capability interface sets.
       "shell:explicit_class": [ ],
 
-      "shell:service_manager": [ "shell::mojom::ServiceManager" ]
+      "shell:service_manager": [ "service_manager::mojom::ServiceManager" ]
     },
     "required": {
       "service:shell": [ "shell:all_users" ]
     }
   }
 }