Use device config to control hints allow list for fill dialog

For the performance consideration, we don't prefer to trigger a
FillRequest for autofill dialog at the Activity starting. We only do
that if one of the fields is a password or contains the allowed
AutofillHints for fill dialog.

Bug: 219844915
Test: set device config, check whether do a fill request at starting
Change-Id: I8cc8c99d1f0e716ad293fa612f65aa2a8d23b028