Reduce UsageStatsXmlV1 log messages.

When parsing newly added fields from Xml database, must catch
the IOException because the new fields do not exist in old Xml database.
This is not really an error. Change Log.e to Log.i, do not print the
full stack.

Change-Id: I5ba86790f7c8eadf4f5dd20d28f9348a23201f87
Fix: 121085733
Test: atest UsageStatsDatabaseTest.java