### Preflight Checklist

- [X] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
- [X] I have searched the [issue tracker](https://www.github.com/electron/electron/issues) for a feature request that matches the one I want to file, without success.

### Electron Version

14.0.0

### What operating system are you using?

Ubuntu

### Operating System Version

Ubuntu 18.04

### What arch are you using?

x64

### Last Known Working Electron version

13.1.7

### Expected Behavior

The buttons in a (native) file dialog read "Cancel"  and "OK"

### Actual Behavior

The buttons in a native file dialog read `gtk-cancel` and `gtk-ok`.

### Testcase Gist URL

https://gist.github.com/Kilian/3de5f404d90d9b12ccaec817fdc4d6da

### Additional Information

Main window has a file input, click it to open the File chooser. Test on Ubuntu between 14.x and 13.x to see the difference. Probably caused by https://github.com/electron/electron/pull/19159

Electron 13.1.7:
![Selection_999(158)](https://user-images.githubusercontent.com/41970/126761063-a5361b8f-d057-406e-bb45-c71d48224b16.png)

Electron 14.0.0-beta.16
![Selection_999(156)](https://user-images.githubusercontent.com/41970/126761068-d6377aee-79f9-47a8-a3b5-f2a96578fda8.png)

shell/browser/ui/file_dialog_gtk.cc
DialogSettings::~DialogSettings() = default;
namespace {
static const int kPreviewWidth = 256;
static const int kPreviewHeight = 512;
void InitGtkFileChooserNativeSupport() {
  
  
  if (supports_gtk_file_chooser_native) {
    return;
  }
  
  supports_gtk_file_chooser_native = false;
  if (!g_module_supported()) {
    return;
  }
  gtk_module = g_module_open("libgtk-3.so", G_MODULE_BIND_LAZY);
  if (!gtk_module) {
    return;
  }
  
  g_module_make_resident(gtk_module);
  bool found = g_module_symbol(
      gtk_module, "gtk_file_chooser_native_new",
      reinterpret_cast<void**>(&dl_gtk_file_chooser_native_new));
  if (!found) {
    return;
  }
  found = g_module_symbol(
      gtk_module, "gtk_native_dialog_set_modal",
      reinterpret_cast<void**>(&dl_gtk_native_dialog_set_modal));