Adjust dream overlay margins for mobile

Introduce smaller margins for the dream overlay in portrait
mode on mobile.
Defined a util with window size bps for dream overlay and
communal hub.
Collect config change in complication hostView controller,
so when screen size changes, we'll update the layout engine
to re-calculate margins.

Bug: b/378163332
Test: atest ComplicationLayoutEngineTest
Test: atest ComplicationHostViewControllerTest
Test: manually on foldable and tablet
Flag: com.android.systemui.glanceable_hub_v2
Change-Id: I7af85f1fc6dfc5cce1710ea9106a2c1627d088dc