Updating submodules
Updating submodules

Summary:
GitHub commits:

https://github.com/facebook/folly/commit/a78842acfdc7579f3774a024d45199a23dfad1b2
https://github.com/facebookincubator/velox/commit/dd6a41cd3aa747de7752bb26923decea3cd4c87c
https://github.com/facebookresearch/multimodal/commit/a3206ebab51157fd78ffcaee111045d725cf8c6c

Reviewed By: bigfootjon

fbshipit-source-id: a0539cb4969e60b5f955a164d85deea9c4424485

facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst