packaging/standalone: Include `rabbit` dependencies when creating the release script

Before this, this was working by chance because those dependencies were
brought by plugins. But if we build the package without any plugins, the
script complains about requires missing applications (kernel and
stdlib), and if we add hard-code them, it complains about other Erlang
applications not listed (sasl, mnesia, os_mon, ...).

packaging/standalone/src/rabbit_release.erl

@@ -54,8 +54,10 @@ start() ->
               end,
 
     %% we need a list of ERTS apps we need to ship with rabbit
-    RabbitMQAppNames = [rabbit | [P#plugin.name ||
+    RabbitMQAppNames = lists:umerge(
-                        P <- rabbit_plugins:list(PluginsDistDir, true)]]
+                         lists:sort(sets:to_list(expand_dependencies([rabbit]))),
+                         [P#plugin.name ||
+                          P <- rabbit_plugins:list(PluginsDistDir, true)])
                        -- PluginAppNames,
     {ok, SslAppsConfig} = application:get_env(rabbit, ssl_apps),