This commit adds the following:
- YAML for istio components to the addons directory (versions with
and without auth)
- logic to copy the appropriate YAML file into the addons manager
dir, depending on ENABLE_ISTIO and ISTIO_AUTH_TYPE env vars
- changes to addon manager script which allow plugins to exist in
namespace other than kube-system. This is needed for Istio
functionality
- additional initialization for Istio in addon manager.