ash: Fix cursor when toggling privacy screen via keyboard key

This CL sets the cursor to remain visible during and after the privacy
screen is toggled via the keyboard key.

Bug: b:147451643
Change-Id: Idb9bf7332d3fea48d015e4acee1d6652f54df754
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2063108Reviewed-by: Jun Mukai <mukai@chromium.org>
Commit-Queue: Gil Dekel <gildekel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#742268}

ash/wm/cursor_manager_chromeos.cc

@@ -70,6 +70,7 @@ bool CursorManager::ShouldHideCursorOnKeyEvent(
     case ui::VKEY_BRIGHTNESS_UP:
     case ui::VKEY_KBD_BRIGHTNESS_UP:
     case ui::VKEY_KBD_BRIGHTNESS_DOWN:
+    case ui::VKEY_PRIVACY_SCREEN_TOGGLE:
       return false;
     default:
       return true;