umbrella podSecurityContext null values are always overwritten by sub-chart default values

[robinliubin]

when install on openshift using umbrella chart.
umbrella can NOT nullify podSecurityContext, if set to null, it will be override by h2oGPT default values.

details in: https://github.com/h2oai/platform-charts/issues/260

need to set below values to empty, not default 1000:

h2ogpt/helm/h2ogpt-chart/values.yaml

Lines 69 to 73 in 6824d21

	podSecurityContext:
	runAsNonRoot: true
	runAsUser: 1000
	runAsGroup: 1000
	fsGroup: 1000

to

  podSecurityContext:
    runAsNonRoot: true
    runAsUser:
    runAsGroup:
    fsGroup: