Handle split screen accordingly after recent transition finished

When a recent transition finished in split screen, make sure to:
1. dismiss the split screen when going to home or launching another
   fullscreen app
2. restore the split screen when returning to a split pair
3. evict privious splitting tasks when entering to a different split
   pair

Bug: 228965939
Fix: 233612774
Test: atest WMShellUnitTests
Test: enable shell transition, trigger split screen and enter overview,
      verified it'll dismiss the split when swipe up to home or switch
      to another fullscreen app
Test: enable shell transition, trigger split screen and enter overview,
      verified it'll restore the divider bar when it returning to the
      original split pair or switching to a different split pair
Change-Id: Ifbfe3baf0abb33f9970fc1a0d36f301cf3b6993a
3 files changed