3/ Remove legacy recents animation logic

- The legacy recents animation logic is no longer supported and
  maintained, this change removes this path and references to
  RecentsAnimationController in the adjacent WM code, leaving only
  the preloading logic

Flag: EXEMPT removing code
Bug: 359608026
Test: atest NexusLauncherTests
Test: atest WMShellFlickerTests
Change-Id: I950dde2f4270171cf3a9bb3caee2e8996ce7f4d4