Helm chart: Support custom path for health check

[theJC]

Describe the solution you'd like

#2938 added the ability to provide a custom path for health check

The router helm chart needs to properly consider that router configuration for health check path (when used) to configure the liveness and readiness probes, and not just use the old hardcoded /health path

Describe alternatives you've considered

Not using the apollo router provided helm chart