isPasswordEnabled and isPatternEnabled return true if used as backup method

When facelock is enabled, isPasswordEnabled or isPatternEnabled will return true depending
on which one is set as the backup method. This is a cleaner way to handle things, rather than
specific cases for facelock in all the methods that call these functions.

Change-Id: Iacb802b89626dfc13f2306de1a2e622ca9b69427