Don't lose content change during rollback for loader already started

Framework edition

If a loader is already started when we try to rollback a content
change, force a new load instead of simply setting the flag to refresh
next time.

Bug 28406183

https://code.google.com/p/android/issues/detail?id=208278

Change-Id: If11d79088d30dd2dc48cf1b3d2882f3712b6cddb