Fix widget cross-talk between users due to Settings widget

Bug: 7247911
Bug: 7294899

Also did some cleanup of unused code that resulted from refactoring
the app widget service. Fixed a few more ambiguous calls that weren't
using the correct user id.
Added some logging and improved the dump() formatting.

Change-Id: I27abb5c6341458e1e50a2cc9ab67e8de573ab283