Deprecate CNNModelHelper - VGGA()
Deprecate CNNModelHelper - VGGA()

Summary:
This diff deprecates `CNNModelHelper` in `VGGA()` function.

Depends on D5247946

Reviewed By: harouwu

Differential Revision: D5248848

fbshipit-source-id: ede9113edb2024e4db8f0048f812050233e3fb40

sf-wind/caffe2,pietern/caffe2,sf-wind/caffe2,xzturn/caffe2,Yangqing/caffe2,bwasti/caffe2,xzturn/caffe2,bwasti/caffe2,xzturn/caffe2,pietern/caffe2,pietern/caffe2,davinwang/caffe2,bwasti/caffe2,sf-wind/caffe2,bwasti/caffe2,Yangqing/caffe2,Yangqing/caffe2,xzturn/caffe2,sf-wind/caffe2,pietern/caffe2,caffe2/caffe2,pietern/caffe2,davinwang/caffe2,davinwang/caffe2,xzturn/caffe2,davinwang/caffe2,Yangqing/caffe2,Yangqing/caffe2,bwasti/caffe2,sf-wind/caffe2,davinwang/caffe2