5/ Remove unused recents code

- The shell transit flag is already hardcoded to true in Launcher
  so we can remove the non-shell transit paths
- The minimized split was from legacy splitscreen where launcher would
  show in a minimized state, which is no longer the case

Flag: EXEMPT bugfix
Bug: 359608026
Test: atest NexusLauncherTests
Change-Id: Idea46fc065485233b9e508dae3ebc4ee87c29ba6
Signed-off-by: Winson Chung <winsonc@google.com>