Test app deploy helm chart also deploys postgres

[izgeri]

The application deploy helm chart is missing Postgres, which the app will require to run.

The kubernetes-conjur-demo scripts use a custom build of Postgres for K8s and a RH out of the box image for OpenShift. If possible, we should try to use an OOTB image for PG in K8s too.

Note: we also want to make sure on deploy we wait for the pg container to be ready via readiness probe.

AC:

• App deploy helm chart includes postgres deploy with readiness probe for K8s apps