Pin Linux image and modules version to 4.4.0-166 (#29690)
Summary:
When installing the 4.4.0-168 version, the following error is thrown (e.g. in https://app.circleci.com/jobs/github/pytorch/pytorch/3577840):
```
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
linux-image-generic : Depends: linux-image-4.4.0-168-generic but it is not going to be installed or
linux-image-unsigned-4.4.0-168-generic but it is not installable
Depends: linux-modules-extra-4.4.0-168-generic but it is not installable
Recommends: thermald but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
```
The (temporary) solution is to pin the Linux image and modules version to 4.4.0-166.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29690
Differential Revision: D18466043
Pulled By: yf225
fbshipit-source-id: d3c69c9ab3bf505c6eb3a2edd138e9789b62b6d6
