k8s-api and lease settings convergence

[ignasi35]

Reference settings for Kubernetes-API and Lease are very similar but slightly different in syntax and features.

It'd be less surprising if they converged. Some examples of differences:

akka-management/lease-kubernetes/src/main/resources/reference.conf

Lines 8 to 16 in 3c564e2

	# Host for the Kubernetes API server. Typically this will be set via an environment
	# variable that is set when running inside Kubernetes
	api-service-host = "localhost"
	api-service-host = ${?KUBERNETES_SERVICE_HOST}
	# Port for the Kubernetes API server. Typically this will be set via an environment
	# variable that is set when running inside Kubernetes
	api-service-port = 8080
	api-service-port = ${?KUBERNETES_SERVICE_PORT}

vs

https://github.com/akka/akka-management/blob/3c564e204d/discovery-kubernetes-api/src/main/resources/reference.conf#L12-L16

2. supporting non-TLS API (only on the Lease implementation)