Unable to set alt+space as keybinding on lastest canary build

[e82eric]

Windows Terminal version

terminal-1.23.3582.0

Windows build number

1.23.3582.0

Other Software

Windows 10

Steps to reproduce

Update Terminal.DuplicatePaneAuto in settings.json that comes with portable build to

        {
            "id": "Terminal.DuplicatePaneAuto",
            "keys": "alt+space"
        }

Expected Behavior

Pane to be duplicated

Actual Behavior

Nothing happens. (System menu also doesn't show)

[e82eric]

It looks like this was introduced in 8bbf00e #18215

In the previous commit I would see TermControl::_KeyDownHandler fire when alt+space pressed, that no longer fired when I moved to 8bbf00e

terminal/src/cascadia/TerminalControl/TermControl.cpp

Line 1611 in 8598ed7

_KeyHandler(e, true);

I think it has to do with this method being removed but I wasn't quite sure how to try adding it back.
https://github.com/microsoft/terminal/pull/18215/files#diff-3b81ed111402e0dc05d8467fc9819ae836970109c26b252fa82019bebf1a8cd5L176

[e82eric]

Duplicate of #18331