Set shelf screenshot landscape size and window insets

Make sure we're respecting nav bar/display cutout/etc insets, and set
the size of the preview so that the height in landscape is the same as
the width in portrait.

Bug: 332737483
Test: manual (visual changes)
Flag: ACONFIG com.android.systemui.screenshot_shelf_ui2 TEAMFOOD

Change-Id: Iaf4aebddaaa34f1ddcb7c9775e96ffd0b2133af2