Remove dragging from/to status bar from proto 1

Removing option to switch windowing modes by dragging from/to status bar
from prototype 1.
Only way to toggle windowing modes is the quick settings toggle.

Bug: 266711813
Test: atest DesktopModeWindowDecorViewModelTests
Test: manual, try to drag a window to status bar when desktop mode is on
Test: manual, turn off desktop mode, check that window handle is not
  shown in status bar
Change-Id: Ia2d4c6f82c9edf2824e263743d1152ea45902ff6