Reland "Separate desktop and fullscreen carousel"

This reverts commit a555f4ca, and relands commit 9420ba75.

- attachAlpha should only be reset in onRecycle, otherwise applyLoadPlan or moveRunningTaskToFront will unexpectedly reset it via resetViewTransforms. This fixes TaplTestsQuickstep.testQuickSwitchFromApp which assert all visible task must be on the left hand side of the screen during swipe up

Fix: 353950224
Change-Id: If1c1524e435c8007844bcd51d8695a6d3b00450b