Update correct split task Id to RecentsTaskController...

Otherwise there will show incorrect/non-exist task pair which doesn't
align with StageCoordinate, also can launch incorrect tasks.
After switch to shell transition, we cannot determine which one is
the top visibile task because the TaskInfo#isVisible will always be
true for both open and close task before transition finish, so
getTopVisibleChildTaskId can choose the close task as top task during
transition, which will accidentally add or remove correct task pair to
RecentTasksController, thus create the strange pair in #getRecentTasks.
Add a field isVisibleRequested in TaskInfo, so there should always one
visible task in a stage, to fix the confuse situation.

Bug: 286204636
Test: follow issus description.
Test: verify split bounds doesn't change after pair-to-pair switch.
Test: Create two pair, drag app from taskbar to one of the pair, do
pair-to-pair switch, enter recents. Verify previous pair still exists,
and no extra pair shows up in recents.

Change-Id: Id468ee889b90411d53fcae574ed65bfa7ab795d2