Fixing rotation issues.

- Ensuring that we can update the stack bounds of non-docked stacks upon
  rotation while split screen is enabled (previously disabled)
- Fix issue where subsequent bounds calculations were using the animation
  target bounds from the prior orientation

Bug: 36657966
Test: android.server.cts.ActivityManagerPinnedStackTests
Change-Id: I810e35f907721ef5c781b914adac3273ea8da5c8