Static TCAgen2 has been migrated to helm deployment in H release (https://git.onap.org/oom/tree/kubernetes/dcaegen2-services/components/dcae-tcagen2). However  TCAgen2 deployments requiring policy based configuration are ONLY supported through Cloudify workflow currently. 

This task is prep TCAGen2 to migrate/support Policy configuration recieved through a file (which will be mounted by Policy sidecar container -  https://wiki.onap.org/display/DW/Policy+function+as+Sidecar)

To preserve backward compatibility with Cloudify deployments (which will continue to CBS api to fetch policies), a new application configuration (boolean) must be added to determine if legacy flow (via CBS) or file based policy (via policy-side car)  should be used.  The property will be disabled in Cloudify deployments and enabled for Helm.  When enabled, application should periodically poll the file and load new policies when available (poll frequency can be managed through application config).