Bring all tiled tasks to front upon tiling tasks.

Bring all tiled tasks to front upon tiling a new task, to avoid weird
looking UI when one tiled task is hidden behind other tasks, and another
one in front.

Flag: com.android.window.flags.enable_tile_resizing
Test: Unit tests and on device testing
Bug: 416770975
Change-Id: If544b1122d0c162eb04e40067b2777d0ab1df3e0