Fix potential leakage of InputWindowHandle from display removal

In general, input info is updated asynchronously by setInputWindowInfo.
So there may be a timing:
(1) Send a input info transaction.
(2) Clear input info for display removal.
(3) The transaction of (1) arrived.
This change ensures that (2) will be called after (3).

Bug: 126141550
Test: Run "atest WindowFocusTests" many times.
      Check "adb shell dumpsys input | grep Display:"
      It should only print "Display: 0".

Change-Id: Iffc867e1630f8b0715faef346c2ecb9210312d9f