Rename conservative.Kernel path to ck

Change-Id: Ia49a97353c02aa2325f0928103eb12cc0448fe31
Update default.xml

Change-Id: I5735cf96e3bfea208db49c62a067cc7bd48f7fb8
Track conservative.Kernel branch jb3-jss

Change-Id: Ide16cd799ec862d68c5c504c5678f0597352b8f4