Support zen rules with INTERRUPTION_FILTER_ALL

This was already mostly supported. In this CL:
* We skip such rules when calculating consolidated policy (they should apply no filtering criteria, and accidentally could if _other_ rules were also active).
* We log whenever rules are activated or deactivated, even if the resulting DND state is unchanged and ZEN_MODE_OFF (previously this was not logged).
* We don't log a DNDPolicyProto if DND is off (more accurate with actual behavior).

Test: atest ZenModeHelperTest
Bug: 308673419
Change-Id: I49518027f74e7d8e7f641b783899f98e4992120a