Change Readiness and Liveliness probe of ONOS helm Chart

Transition:
In the onos-kubernetes charts we use a `check-onos-status` script that I couldn’t find in onos-2.2
https://github.com/opennetworkinglab/onos-kubernetes/blob/master/charts/onos/templates/deployment.yaml#L56
The closes thing I could fin is `onos-check-node-status` which check the readiness of all the given nodes.
I think this is ok for liveliness, pending we issue it to each instance separately and check each one of them.
For readiness, while talking to amit we thought about using the state of certain apps, for example in voltha we want `aaa,dhcpl2relay,olt,sadis` to be present and active for ONOS to be considered "ready".
This could probably achieved with the `onos-check-apps`.

Readiness should be different then liveliness because the `READY` state of an instance does not actually make into account apps.