Strengthened film grain setting.
Strengthened film grain setting.

This patch increases the preference for maintaining similar variance
between source and reconstruction and thus helps improve film grain
retention.

The changes are only active when film mode is selected

Change-Id: I3bc082dca678a0f32ec00f30f5d90d0f95ca2381

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