YAAFFFCR - Yet Another Android Autofill Framework Field Classification Refactoring.

The field classification service is moving to another process, hence we need
to get the scores in a batch and handle the results in a callback.

Test: atest CtsAutoFillServiceTestCases:FillEventHistoryTest \
            CtsAutoFillServiceTestCases:FieldsClassificationTest
Bug: 70939974

Change-Id: I0de91f18828872c455abd1609d3a3890ddc3bd4f