Fix wrong divider position after rotation

Ratating from 270 -> 0 -> 90 keeps wrong "mNonDecorInsets" in the
DisplayLayout of split screen due to not updating insetsState when
insetsChanged. Updtaes to stop house keeping DisplayLayout separately in
split screen component by fetching it from DisplayController directly.

Cherry picked Ica32c817ef414f550931a50ec919e3114a075e2c to master due to b/286408867.

Code was merged via `-s ours` and is missing even though the sha exists on the target branch. Cherry pick is required to bring in the code.

Manually remove the "Merged in" directive to allow for downstream propagation.

Fix: 285854252
Test: atest WMShellUnitTests
Test: manual by issue steps:
  1) Launch apps to enter split-screen mode
  2) Rotate to 270
  3) Rotate to 0
  4) Rotate to 90
  5) Expect the position of split-tasks is right
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:1ffdf22a145a13c79cc15612f6b0b9bd043d7b24)
Change-Id: I5e087d163c0ed793a3d9552d463e43300c7115cc