Update API deployment chart to conditionally load liveness/readiness probes

[jcadam14]

Some services that we reuse these charts with might not have a way to health probe the container, or like the locust service it's a run and done concept.

Add {{- if (default true .Values.healthChecks) }} around the probes to make them optional, defaulting to true so we don't have to update the other override values for this.