Add logging to KeyguardNotifVisProvider

Specifically, dump() the state tracked within the provider, and log when
the notif pipeline is invalidated due to a state change from the
provider (as well as what exactly changed).

Bug: 234824085
Test: manual
Change-Id: I608b857c9796ed37ba75ca51d8ab0d95df754fa4
Merged-In: I608b857c9796ed37ba75ca51d8ab0d95df754fa4