Eliminate delay before contacts lookup for a Notification

The RankingReconsideration produced by ValidateNotificationPeople had getDelay() == 1000 ms, which meant NMS waiting a full second before starting the work. This wasted half of the time available to decide whether a notification should produce sound during DND, for no good reason (despite what the comment claimed, this delay is not used as a timeout).

This CL also moves all the contacts-querying methods in ValidateNotificationPeople to PeopleRankingReconsideration. This makes it clear that the querying is only done as part of the reconsideration, and process() only queries the cache.

Bug: 263839687
Test: atest
Change-Id: I53e8ce49de004d66f4790fa29fc11dbf0ef8c8e2