CB: Add system property to enable/disable dup detection

If system property persist.cb.dup_detection is set to false, duplicate
detection is disabled.  If it is set to true, duplicate detection is
enabled.  If the system property does not exist, using true/enabled
as a default value

Change-Id: If377675c46950b4a03253fa29c2d8ae1c5804544
1 file changed