More durable logging around system app upgrades.

We've been seeing some really funky behavior when upgrading or
downgrading system apps around OTA time.  Put more of these one-time
logs into durable storage to help investigate.

Bug: 17805839
Change-Id: If898d7df229c1f71e598b0d965325c272060e5e7
diff --git a/services/core/java/com/android/server/EventLogTags.logtags b/services/core/java/com/android/server/EventLogTags.logtags
index 5aaeb6a..99a1254 100644
--- a/services/core/java/com/android/server/EventLogTags.logtags
+++ b/services/core/java/com/android/server/EventLogTags.logtags
@@ -134,6 +134,8 @@
 # + check activity_launch_time for Home app
 # Value of "unknown sources" setting at app install time
 3110 unknown_sources_enabled (value|1)
+# Package Manager critical info
+3120 pm_critical_info (msg|3)
 
 
 # ---------------------------