can't reference file when updating condition sets

[strantalis]

When I go to update subject condition sets I only see the following flags. It would be nice to also allow the ability to point to a file like on the creation of a condition set.

Usage:
  dsp tructl policy subject-condition-sets update [flags]

Flags:
      --force-replace-labels   Destructively replace entire set of existing metadata 'labels' with any provided to this command.
  -h, --help                   help for update
  -i, --id string              The ID of the subject condition set to update
  -l, --label strings          Optional metadata 'labels' in the format: key=value
  -s, --subject-sets string    A JSON array of subject sets, containing a list of condition groups, each with one or more conditions