[Shell Transition]Fix live tile be hidden by wallpaper leash.

A generic fix to specific layers for live tiles/wallpaper.
Because there cannot sure the absolutely z-order of recents surface, we
can always set wallpaper layer to bottom, and set the z-order of live
tiles to either MAX or MIN + 1, so live tile can always above wallpaper,
also the live tile can be show above/below recents surface based on
mDrawsBelowRecents.

Test: enable shell transition, open app then entering recents, verify
the live tile stay visible when entering recents. And the shared
indicators visible when state transition complete.
Test: also verify above test for legacy transition.
Bug: 236410500

Change-Id: I0f86d7617af1d96c28783320248af64f576bd570