Fix a bug to not complete the augmented autofill request when fill window is shown

* The bug was introduced in ag/11784240 causing the existing CTS test to
  fail: android.autofillservice.cts.augmented.AugmentedLoginActivityTest
  #testCancellationSignalCalled_retriggerAugmentedAutofill
* Basically when the dropdown fill window is displayed, we should not mark
  the augmented autofill request as complete

Test: atest android.autofillservice.cts.augmented
Test: atest android.autofillservice.cts.inline
Bug: 158864213
Bug: 158038231

Change-Id: Ifb75189c1ba3183c99516bfb9a7053524f4bbddc