Show split screen action for each task

Remove previous condition:
1. `taskView.containsMultipleTasks()` - there is already a check to filter out "Split screen" item: https://googleplex-android.googlesource.com/platform/packages/apps/Launcher3/+/refs/heads/main/quickstep/src/com/android/quickstep/TaskOverlayFactory.java#68

Edit previous condition:
2. `notEnoughTasksToSplit` - condition saying if there is less than 2 recent tasks. We still should give the possibility to split the screen if Taskbar is not presented

Bug: 305958994
Flag: NONE
Test: manual - took a photo (https://screenshot.googleplex.com/7doU5z9AjxxETUo)

Change-Id: I3fdfea987c426d557a91b0a25af368069e8af3f8