Create container data directory on startup if it doesn't exist

src/anbox/cmds/container_manager.cpp

@@ -79,6 +79,9 @@ anbox::cmds::ContainerManager::ContainerManager()
       if (!data_path_.empty())
         SystemConfiguration::instance().set_data_path(data_path_);
 
+      if (!fs::exists(data_path_))
+        fs::create_directories(data_path_);
+
       if (!setup_mounts())
         return EXIT_FAILURE;