PACKAGE_CHANGED is called when either the application or any
of its components change. Rework old early exit code to
handle component-level disabling wrt listeners.
Note PACKAGE_CHANGED can take quite a while to reach NMS.
Up to ten seconds (!) after component-disabling in app.
Bug:8982243
Change-Id: Ia325516140dd9288466a663192a5326019f071ab