Deferring add splash screen window when launch with startActivities

There should only need to create one splash screen window for the top
activity when launch with startActivities, but there would create
starting window for each activities and make extra calls to WMShell,
which is not necessary, so we can queueing the status and activities
while startActivities, and use the status to create a starting window
to the top-most activity.
This also fix the other limitation that ActivityOptions can only apply
to the top activity.

Bug: 194367428
Bug: 203497083
Test: atest ActivityRecordTests ActivityStarterTests
Test: atest SplashscreenTests
Test: verify launch app with startActivities and WMShell should only
receive one addStartingWindow request.

Change-Id: I759da20e585f54a6e86e20153c2b4aa35017c1f6