Prevent the splashscreenview be replaced after transfer starting window

The splashscreenview can be replaced if starting window was transferred
and the first starting window didn't added success.
There should verify the appToken before setViewSynchronized set the
splashscreenview back to the container.

Issue sequence:
- Start first activity A, core request to add a starting window for it.
- Start second activity B, core try to transfer starting window from A
to B but since the window haven't added back,  there will trigger to
add a new starting window for B.
- SystemUI add starting window to A but added fail because there was
transferred.
- SystemUI add starting window to B, success.
- Choreographer post setViewSynchronized to add view for A and B to the
container, because we only verify by taskId, so the SplashscreenView was
overwrite by A.
- After reveal animation finish, SplashScreenView#post will not be
executed because this view was not on screen.

Fixes: 188540606
Test: atest StartingSurfaceDrawerTests
Test: Open twitter from notification.
Change-Id: I894da75827556d3c1bc8bb0656196102de5a6847