Menu is toggled with right alt (aka Alt Graphics aka AltGr)

[bsclifton]

Did you search for similar issues before submitting this one?
Yes

Describe the issue you encountered:
The right alt key (AltGr) on Windows is not distinguished from the traditional alt key. This results in the menu being toggled when pressed.

Expected behavior:

• Platform (Win7, 8, 10? macOS? Linux distro?):
• Brave Version:
  0.12.4
• Steps to reproduce:
  1. Use Brave on Windows and visit http://fsymbols.com/keyboard/windows/alt-codes/list/
  2. Ensure hide menu by default is enabled
  3. Send focus to the demo text field, hold AltGr and then hit 1 to type a smiley face ☺
  4. Notice menu was toggled
• Screenshot if needed:
• Any related issues:

[bbondy]

Pls also add issue to milestone when a PR is marked for the same milestone, thx!