Symlink /home as /usr/home

Some software still expect $HOME to be /usr/home, not /home or per environment.

Fixes the following error:

$ pre-commit
An error has occurred: InvalidManifestError:
=====> /usr/home/dereckson/.cache/pre-commit/repoyyalm8z4/.pre-commit-hooks.yaml is not a file

Test Plan: Deployed on WindRiver.

Differential Revision: https://devcentral.nasqueron.org/D4143