st2.packs.images and st2.packs.volumes Default Empty Maps

[ericreeves]

Updated values.yaml to include empty maps for st2.packs.images, st2.packs.volumes.packs, st2.packs.volumes.virtualenvs, and st2.packs.volumes.configmaps to avoid these helm-operator warnings for any flux users:

helm-operator-5c4bf67767-fffpp:helm-operator ts=2021-06-19T11:57:41.915841444Z caller=logwriter.go:28 info="2021/06/19 11:57:41 warning: destination for packs is a table. Ignoring non-table value <nil>"
helm-operator-5c4bf67767-fffpp:helm-operator ts=2021-06-19T11:57:41.915859845Z caller=logwriter.go:28 info="2021/06/19 11:57:41 warning: destination for virtualenvs is a table. Ignoring non-table value <nil>"
helm-operator-5c4bf67767-fffpp:helm-operator ts=2021-06-19T11:57:41.915865914Z caller=logwriter.go:28 info="2021/06/19 11:57:41 warning: destination for configs is a table. Ignoring non-table value <nil>"
helm-operator-5c4bf67767-fffpp:helm-operator ts=2021-06-19T11:57:42.216291548Z caller=logwriter.go:28 info="2021/06/19 11:57:42 warning: destination for packs is a table. Ignoring non-table value <nil>"
helm-operator-5c4bf67767-fffpp:helm-operator ts=2021-06-19T11:57:42.216317898Z caller=logwriter.go:28 info="2021/06/19 11:57:42 warning: destination for virtualenvs is a table. Ignoring non-table value <nil>"
helm-operator-5c4bf67767-fffpp:helm-operator ts=2021-06-19T11:57:42.216324314Z caller=logwriter.go:28 info="2021/06/19 11:57:42 warning: destination for configs is a table. Ignoring non-table value <nil>"

[cognifloyd]

Thanks. cherry-picked your changes.