vp9: Fix an issue with setting variance thresholds.
vp9: Fix an issue with setting variance thresholds.

From commit:
https://chromium-review.googlesource.com/c/441393/

On non-segment the set_vbp_thresholds() should be called
again to adjust thresholds based on content_state of superblock.
This was the intended behavior from 441393.

Small change in RTC metrics and speed.

Change-Id: I45e5fbdc4af74db76b3cb4f13074fcae0eb2219e

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