Fix system zen rules by using owner package name if caller is system

Previously were unable to add new zen rules because rules added via the settings pages were getting registered under package "com.android.settings", which then were not considered "system rules". These rules should have package android, so when we can trust the caller (via checking that the caller is system) we should be taking the package name from the owner of the rule.

Bug: 245236706
Bug: 242537431
Test: NMSTest; manual

Change-Id: Id69b671592396ac3304862dadbe73de328a8e27a
Merged-In: Id69b671592396ac3304862dadbe73de328a8e27a