Fixed Alt+PrtSc key combination is not recognized by Brave

[srirambv]

Test plan

1. Launch Brave on Windows and ensure "auto hide menu" is true
2. Confirm menu shows/hides when pressing ALT by itself
3. Hold ALT and then press print screen. Let go of keys
4. Confirm menu is not shown
5. Open "pbrush.exe" and paste clipboard there
6. Contents should be the picture you just took

Original issue description

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

• Describe the issue you encountered:
  While testing Menu on Windows now properly responds to ALT #7485 , it was found pressing Alt +PrtSc and releasing the keys still enables the menu bar. PtrSc is not recognized by Brave which causes it to only to register pressingAlt which causes the menu to be shown

• Platform (Win7, 8, 10? macOS? Linux distro?):
  Windows 10 x64

• Brave Version (revision SHA):
  c789de1

• Steps to reproduce:

  1. Build from c789de1 branch
  2. Press Alt +PrtSc and release the keys
  3. Menu bar is activated

• Actual result:
  Menu bar is activated when Alt +PrtSc combination is pressed

• Expected result:
  Should not show menu bar when Alt +PrtSc combination is used

• Will the steps above reproduce in a fresh profile? If not what other info can be added?
  Yes

• Is this an issue in the currently released version?
  Yes

• Can this issue be consistently reproduced?
  Yes

• Extra QA steps:
  1.
  2.
  3.

• Screenshot if needed:

• Any related issues:
  Menu on Windows now properly responds to ALT #7485
  cc: @bsclifton

[luixxiul]

Note: on VirtualBox you will need to send the key combination via the main menu (input -> keyboard -> send alt printscreen).