Handle racey readiness probe in conduit containers

[lyuboxa]

The conduit server container will exit when the pipeline goes into degraded state (see pipelines.exit-on-degraded config option).

However, during the load up phase the probe can report ready even though conduit has not loaded the pipeline

time	conduit	container status
T1	Conduit boots /healthz 200	Container Ready
T2	Conduit loads pipeline /healthz 200	Container Ready
T3	Conduit exits due to pipeline failure /healthz not reachable	Container Not Ready

Temporary solution may be to introduce a delay such that conduit has a chance to load the pipeline and either stabilize or exit, e.g.

Delay of t = 2

time	conduit	container status
T1	Conduit boots /healthz 200	Wait
T2	Conduit loads pipeline /healthz 200	Wait
T3	Conduit exits due to pipeline failure /healthz not reachable	Check