Changed FillResponse.setAuthentication() to require field ids.

Currently, authenticate FillResponses do not support partition and follows
the "Highlander approach" (There can be just only one), which causes the
authentication UI to show on all views.

This CL overloads FillResponse.setAuthentication() so it requires the
AutofillIds of the autofillable fields, although behind the scenes it
calls the old method - once clients use the new method, the old method
will be removed and the underlying implementation changed.

The new behavior will be tested by testFillResponseAuthJustOneField()
on LoginActivityTest, although currently it's testing the old behavior.

Test: LoginActivityTest.testFillResponseAuthJustOneField

Bug: 35707731
Bug: 36855717

Change-Id: I601f3e4776aa8763415a06d8d802901a930728d2