Split Healthcheck start interval into its own default value as per docs

[saltydk]

Description

Is there a particular reason that the start interval inherits the value from regular interval?

moby/daemon/health.go

Lines 253 to 255 in a33b302

	probeInterval := timeoutWithDefault(c.Config.Healthcheck.Interval, defaultProbeInterval)
	startInterval := timeoutWithDefault(c.Config.Healthcheck.StartInterval, probeInterval)
	startPeriod := timeoutWithDefault(c.Config.Healthcheck.StartPeriod, defaultStartPeriod)

Docs indicate that the default is 5 seconds: https://docs.docker.com/reference/dockerfile/#healthcheck

This request is to have it defined as its own default value as per the docs.

I apologize if I have misread the code as I am not a Golang programmer.

[neersighted]

cc @cpuguy83

[cpuguy83]

I think this was just an oversight.

[j2walker]

Hi @vvoland, I am a student from UT Austin taking a class about virtualization and containerization (CS 360V). Could I tackle this bug fix?

[cpuguy83]

Please do.