Route PredictedAppIcon clicks through launcher

* This allows us to intercept launching predicted apps for
split-screen if user is in split selection flow
* Defaults to existing behavior of ItemClickHandler.INSTANCE
if we do not need to intercept the click

Bug: 276361926
Flag: ENABLE_SPLIT_FROM_WORKSPACE_TO_WORKSPACE
Test: Launches as expected when not in split, launches in
split when selected as second app to initiate split with

Change-Id: Ieb45137ae89da340d314e995f4f6eb1f8b49a42f