Fix Settings app crash after enabled multi-user

Bug: 8128225
Change-Id: I2918a5ec36e861a1ce4b2e67cf7607929732a7bf
Prevent cursor from causing global reference leaks.

To fix this the ContentQueryMap needs to be closed
when onStop is called so any global references can
be reclaimed.

Change-Id: I0c679c10b0d75ab0aac2fe499563c57d934e318a
avoid stopping app in case of accessing empty db

When accessing empty database, Setting App is stopped, sometimes.
To avoid stopping app, check null for cursor

Change-Id: I71ec067f502d12a9215a9abdbe9e23fc07af17bb
Fix not updating error message when authentication fails

If attempt to configure the first network fails, AccessPoints fails to
update error message because it only checks the error code if it is not
active.

With this change, user may see saved network message for a second
because SupplicantStateTracker retries on authentication failure so
intermediate status is displayed between each trial.

Bug: 8284024
Change-Id: I8b976b03878e27e46726ee8a176f131115b7a409