Add a new API to report display hotplug events

When a display is connected, error may occur, this new api introduces
an event variable to specify the hotplug event, including errors.

This new api should be used, and the old onHotplug method is deprecated.

Bug: 241286153
Test: manual
Change-Id: I20ea685c5012015836024e7cab4dc0e68ebb835f