vp9: Add scene change detection flag to cyclic refresh setup
vp9: Add scene change detection flag to cyclic refresh setup

Disable cyclic refresh on slide/scene change frame. It was already
disabled on the re-encode for the slide change, but this change
makes sure its always disabled on a detected slide change (which
may not be re-encoded at high Q).

Change-Id: I1195c855bca25985d4d41e5b657adf124e901760

webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx