Initial Desks tracking on Launcher

This CL adds the initial implementation of the desks tracking
on the launcher side inside `DesktopVisibilityController`.

Bug: 392986431
Test: m
Flag: com.android.window.flags.enable_multiple_desktops_frontend
Flag: com.android.window.flags.enable_multiple_desktops_backend
Change-Id: I7ece2407a03fec1cad4663efa230ec9a1980fb75