It provides an easy way to run commands to quickly test gVisor.
By default it maps the host root as the container root with a
writable overlay on top (so the host root is not modified).
Example:
sudo runsc do ls -lh --color
sudo runsc do ~/src/test/my-test.sh
PiperOrigin-RevId: 243178711
Change-Id: I05f3d6ce253fe4b5f1362f4a07b5387f6ddb5dd9