bd-rate-report: libvmaf's apsnr-y,u,v, not included

[vibhoothi]

Right now in the bd_rate_report computation
APSNR Y, U, V is not computed even tho it is calculated and written to .out files in the rd_tool.

[vibhoothi]

This will be useful when we remove the old daala-metrics
xiph/rd_tool#89