Shrink oversize windows after dragged to a smaller display

This change shrinks oversized windows to ensure they fit when dragged to
a new display.

An "overhang area" is defined by extending each edge of the display with
a small margin. The new constrainBoundsForDisplay function uses this
area by:
- Clipping resizable windows to fit within the overhang area.
- Scaling non-resizable windows down to fit the overhang area,
  preserving their aspect ratio.

Flag: com.android.window.flags.enable_shrink_window_bounds_after_drag
Bug: 403486903
Test: manual
Change-Id: I31b7f3fb6bd7d56d55b783891e11027c994873b3