Update to FIDL2 String interface (#4775)

content_handler/application_controller_impl.cc

@@ -89,7 +89,7 @@ fdio_ns_t* ApplicationControllerImpl::SetupNamespace(
     }
     zx::channel dir = std::move(flat->directories[i]);
     zx_handle_t dir_handle = dir.release();
-    const char* path = flat->paths[i].data();
+    const char* path = flat->paths[i]->data();
     status = fdio_ns_bind(fdio_namespc, path, dir_handle);
     if (status != ZX_OK) {
       FXL_LOG(ERROR) << "Failed to bind " << flat->paths[i] << " to namespace";