Fix launcher crash and correct split behavior

Fix laucher crash while swipe up in split screen. This issue caused
by launcher will request 3 runningTaskInfos to do some action,
however, it cannot ensure 3 info actually include both splits because
only one got focused. Fix this by WA on RunningTasks, update the
adjacent task of the focus one too to make sure both split task
will be top two while calling getTasks.

Correct some split behavior while startTasksWithLegacyTransition
too.

Bug: 211716649
Test: pass existing tests.
Test: Make many split pair then swipe up
Change-Id: I2e6deb2ac607b454ca8fc760f0399135a1e8e901
Merged-In: I2e6deb2ac607b454ca8fc760f0399135a1e8e901