Switch engines using keyboard shortcut doesn't update its icon.

## What Happened

When using multiple keyboard input method
Default shortcut Ctrl + Space does change input method (switch engine), but does not change the Input method indicator icon on top right (the "en" thing in the image).

while switching engines inside Settings app or Wingpanel widget works as usual.

## Expected Behavior

Default shortcut Ctrl + Space should also change the Input method indicator on top right.
That way people will know if they are using the right engine for the right language.

## Steps to Reproduce

1. Enable Ibus Daemon and add a second input method.
2. Close System Settings app, then heads to any text field (Code app for example)
3. Using shortcut to switch engine (Default Ctrl + Space) and try typing. Notice that input method did change but not the top right indicator.

### Logs

## Platform Information

Latest version of Elementary OS 6 with all app updated (Aug 11 2021).