Removing dependencies on recents-specific code in SysUI

- Removing references to SystemServicesProxy (to be removed) for
  AM/WMWrapper
- Removing unused code for old nav bar swiping logic, and also unused
  and quickstep-incompatible code for dragging in recents
- Removing all event bus logic from outside recents subpackage
- Exposing PipUI component for bridge caller

Bug: 114137554
Test: Can still swipe up
Change-Id: Ibcfbe06acae06ea5950615cabd52243279fee16d