Don't allow null ids on FillResponse.Builder.setAuthentication()

It would crash the system when save is invoked.

The issue was reproduced by passing a null id on
AuthenticationTest#testFillResponseAuthServiceHasNoDataButCanSave , but that
change was not committed because with the fix the builder would throw an
exception.

Test: atest CtsAutoFillServiceTestCases:FillResponseTest

Fixes: 76097200

Change-Id: Ifa8105ee1451ba7107082a94a538a8f84f50df18