Fix the gap between notification and smartspace is too large in large

screen portrait mode

It's caused by topPadding is not substracted from notification bounds,
and the top margin is added to the position of notification twice.

Bug: 349955447
Test: manually test the position of notifications in large screen
portrait, landscape mode and normal screen portrait mode.
Flag: com.android.systemui.migrate_clocks_to_blueprint

Change-Id: I7343b3dfdc718f49139d0ef62e2dcfc26cc1205b