Introduce `NoOpResolverComparator`.

We can use this as a "default" ranker in cases where we already know
the desired ranking from the client (subclass/caller) request, as in
`NfcResolverActivity`.

Test: new unit test
Bug: 327665515
Flag: EXEMPT bugfix
Change-Id: Ie3a7c1d061c5834559d5a15d1ceca1c12613ce60
3 files changed