Menu is not shown when Electron on Linux is switched to full-screen mode

[westbury]

Steps to Reproduce:

1. Run the desktop example on Linux
2. Press F11 to switch to full-screen
3. Note that the menu is missing

Additional Information

• Operating System: Linux
• Theia Version: 1.17

For reference the PR that introduced the full-screen feature is #9399

[vince-fugnitto]

@westbury I believe it is the same behavior as in vscode.
I believe the issue is that the menus are still hidden when window.menuBarVisibility = visible and we toggle full screen.

theia/packages/core/src/browser/core-preferences.ts

Line 65 in 10d5275

'Menu is always visible at the top of the window even in full screen mode.',

[vince-fugnitto]

The more appropriate pull-request would be #9830.