Report ActivityId in Content capture ActivityEvent

Currently, the ActivityEvent only reports ComponentName and the event
type. It may be a problem when launching the split mode for tablet.
If the Activity launch mode is standard or singleTop, system allows
to launch the same Activity in split mode. The ContentCaptureService
cannot identify two different Activities instances in the split mode.

To resolve this problem, the system will also report ActivityId in
ActivityEvent to help ContentCaptureService to identify the Activity.

Bug: 245023463
Test: atest CtsContentCaptureServiceTestCases
Change-Id: I8a79633a8ff0e5a99dc154bb4002a418b2e98219