Override on WindowToken if necessary

Override the screen size in Configuration on WindowToken level instead
of WindowState. This will make sure the override is applied when there
are registered change listeners attached to the WindowToken. The
WindowState override is no longer needed as the parent resolved
configuration will be used instead.

Test: Install legacy IME apps, check the Configuration size
Bug: 372592558
Flag: EXEMPT bugfix
Change-Id: I0e1161f2bd376aa73bc4d51373e65e7702c11bb4