Updating uses of ContactDisplayUtils and FBE fix

+ ContactDisplayUtils's preferredName methods now accept the
ContactsPreferences object rather than just an int. This was done to
abstract out the null checks that were previously necessary when using
the utility.
+ Conference calls were crashing because the ContactsPreferences
object was attempting to access shared preferences while File based
encryption locked. This change makes use of the
ContactsPreferencesFactory to handle returning the proper instance
when in this locked case.

Bug=26822105

Change-Id: Ie382c0c615cf27f69682774fc9538828cc429e69