clobber wom: implement onKeyUp for StemPrimaryKeyRule

- Apply the callback for stem primary key. This is helpful for devices
that wish to trigger stem primary key press behavior without waiting
for the delay needed to check for consecutive presses.

- Added a new config, `config_shortPressEarlyOnStemPrimary` to guard
StemPrimary key's usage of this callback. If this config is enabled,
the single press behavior for stem primary key will run in response to
the first key up event, instead of using the `onPress` callback.

Test: atest WmTests:SingleKeyGestureTests
BUG: 297121934
Change-Id: I7ab3ebf2a79b74fb47fb74da80cb6e8d9c04dc87