Connect split-screen things to systemui divider

Since divider stuff lives in sysui instead of framework

Bug: 133381284
Test: Manual, open 2 apps in split and drag-up to show
      recents.
Change-Id: If6740b7ee4829bf4cac6e829e81943f16a41f977
(cherry picked from commit 3ef159becdbda1041781920eb816d041bd88da44)
2 files changed