Send connection event on handover from WIFI to LTE.

Send a connection event when handover from wifi to LTE occurs for a video
call.  This event is only sent once, the first time it happens.

Also added a test intent which can be sent to reset the preference.

Bug: 30837560
Change-Id: Iefc2c4024d4d1956e8a9153345b6c2892bd7c38b