Autofill optimization on notifyViewEntered().

When an autofill service returns a null FillResponse, AutofillManager is kept
in a "zombie" state where the session is finished but a new one must be started
if the user taps another view, so it covers the scenarios where a new view is
added (and the service can autofill it). But we can optimize this workflow by
ignoring views that were already visited before.

Test: atest CtsAutoFillServiceTestCases:LoginActivityTest#testMultipleIterationsAfterServiceReturnedNoDatasets
Test: atest CtsAutoFillServiceTestCases:LoginActivityTest

Bug: 73078981

Change-Id: If8b01aca41f5d1613663002bb6b589fb1cf549df