Use rule package name in addAutomaticZenRule; specify "android" for all system apps

This is a roll forward of two reverted changes combined into one:
commit b6d04416
commit e5e51116

It additionally fixes an issue where in multi-user profiles (such as a guest user), rules would be incorrectly identified as not created by the system and would therefore fail to be created in settings.

Bug: 257477671
Bug: 245236706
Bug: 242537431
Test: NotificationManagerServiceTest; ZenModeHelperTest; manually verified that it's possible to create zen schedules from guest mode
Change-Id: I0c4c705cfe5fc875151958957daaf8657fbc21a7