Yapf fixes on deepchem.feat module

[arunppsg]

Pull Request Template

Description

Fix #3159

This PR, along with #3207 completes yapf updates on deepchem.feat module.

Type of change

Please check the option that is related to your PR.

• Bug fix (non-breaking change which fixes an issue)

Checklist

• My code follows the style guidelines of this project
  • Run yapf -i <modified file> and check no errors (yapf version must be 0.32.0)
  • Run mypy -p deepchem and check no errors
  • Run flake8 <modified file> --count and check no errors
• I have performed a self-review of my own code

[GreatRSingh]

Which directories of deepchem/feat are being indented in this PR #3211.
Asking so that I can indent the remaining directories in my PR #3207.

[arunppsg]

Which directories of deepchem/feat are being indented in this PR #3211. Asking so that I can indent the remaining directories in my PR #3207.

I think most of the yapf fix PRs are landed - I need to check the CI, get them reviewed and merge in. If something is missed out, I will let you know.