Overlay a highlight over autofilled views

Also clear this overlay once the data changes. Some views call
notifyValueUpdated even if the value did not change. Hence remeber the
data that was autofilled and check if the data really changed.

Make the autofilledDrawable publicly accessible so that virtual views
can use the same UI.

As the activity is not aware that the views were autofilled the state
has to be explicitly persisted over activity lifecycle events as part
of the view. The lifecyle does not work yet as the AutofillIds are not
stable over activity lifecycle events.

Fixes: 34946006
Test: Autofilled and changed all supported views.
      cts-tradefed run cts-dev -m CtsUiRenderingTestCases
Change-Id: I58b105bb221f1b6466dd136dfe5062d3babb5aa8