[heartex/label-studio] Sidecar containers args fixes

[benglewis]

Description of the change

In my last PR, I realize now that I was a little hasty and did not implement the args support in the sidecarContainers correctly. This PR fixes the bugs there.

Benefits

Users of sideContainers like myself.

Possible drawbacks

N/A

Applicable issues

N/A.

I didn't open an issue ticket yet, but essentially this is the error that made me realize my mistake:

values don't meet the specifications of the schema(s) in the following chart(s):
    label-studio:
    - app.sidecarContainers.0.args: Invalid type. Expected: object, given: array

Additional information

N/A

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Input Validation completed with values.schema.json.
• Variables are documented in the values.yaml and added to the README.md.
• Changelog updated to describe new changes/fixes.
• Title of the pull request follows this pattern [heartex/<name_of_the_chart>] Descriptive title

[benglewis]

Closed in favor of #67