Tune vbr bit-allocation among various pyr levels
Tune vbr bit-allocation among various pyr levels

lowres (30 frames, vbr):
-0.253% Av PSNR, +0.017% Glb PSNR, -0.415% SSIM

Also does not seem to be slower.

STATS_CHANGED

Change-Id: I059b19c4afc09082e037870fb789427b6d57a26e

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom