add about fragment

Change-Id: I87c22877c64ebbfbe2764f406714480a995793f1
add support fragment

Change-Id: If6731b2544f852d8d14ed05a735c200326a59e87
switch to support fragments, split preference fragments

Change-Id: Ia93d2f79386ae7fb7559bc4b50f42ffd7c701382