Add Coordinators to the NewNotifPipeline

Coordinators added to NotifCoordinators will be passed the
initialized NotifListBuilder and NotifCollection when they're
ready for Pluggables, NotiLfetimeExtenders and NotifCollectionListeners
to be registered.

This CL adds the KeyguardCoordinator which filters notifications based
on whether the keyguard is showing and user lockscreen notifcation
settings

Test: atest KeyguardCoordinatorTest
Bug: 145134683
Change-Id: Ie5a2c0f696a6eedbed203b1b5809164742d23132