job-json-overrides mistakenly applied to other files in `profiles:`

When using the job-json-overrides computation, we mistakenly add job-json-overrides to other files too.

We should fix this issue!

tmp123.yaml

cat tmp123.yaml
config:
  profiles:
    launcher.kubernetes.profiles.conf:
      '*':
        job-json-overrides:
          - name: hi
            target: ho
            json: silver
    profiles:
      '*':
        key: value

helm template rstudio/rstudio-workbench -f tmp123.yaml | grep profiles -A 8
#  launcher.kubernetes.profiles.conf: |
#
#    [*]
#    allow-unknown-images=1
#    container-images=rstudio/r-session-complete:bionic-2021.09.2-382.pro1
#    default-container-image=rstudio/r-session-complete:bionic-2021.09.2-382.pro1
#    job-json-overrides="/spec/template/spec/volumes/-":"/mnt/job-json-overrides-new/defaultSessionVolume.json","/spec/template/spec/containers/0/volumeMounts/-":"/mnt/job-json-overrides-new/defaultSessionVolumeMount.json","ho":"/mnt/job-json-overrides-new/hi.json"
#
#
#  profiles: |
#
#    [*]
#    job-json-overrides="/spec/template/spec/volumes/-":"/mnt/job-json-overrides-new/defaultSessionVolume.json","/spec/template/spec/containers/0/volumeMounts/-":"/mnt/job-json-overrides-new/defaultSessionVolumeMount.json"
#    key=value

Related to #161 (which may render this approach obsolete)

Reproduce the issue with tmp123.yaml using the shown helm template command, then trace how profiles and job-json-overrides are rendered together. Done means the generated launcher.kubernetes.profiles.conf still contains its override while the separate profiles output contains key=value without the job-json-overrides entries; check whether related issue #161 changes the intended approach.