[intra-edge] Use 5-tap filter
[intra-edge] Use 5-tap filter

For intra edge filtering experiment, replace the 2x iteration
(5-6-5) filter with a 5-tap filter (2-4-4-4-2).

BDrate (1 key-frame) for this change:
cif:    +0.02%
midres: +0.04
720p:   -0.01
1080p:  -0.03
4k:     -0.01

BDrate (1 key-frame) for intra-edge experiment:
(05/31, disable rect-tx, ext-tx, delta-q, ext-delta-q)

          1 key-frame     60 frames
         PSNR   SSIM     PSNR  SSIM
cif:    -0.02   -0.01   -0.03  -0.01
midres: -0.02   -0.02   -0.05  -0.10
720p:   -0.36   -0.39   -0.05  -0.06
1080p:  -0.75   -0.88   -0.22  -0.27
4k:     -0.91   -1.12   -0.45  -0.54

Change-Id: I834037e662b4483d4d6bdceb1c1624d56ba293a4

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