Fix buildArgs for dockerfile.v0 schema tests.

[mitchdenny]

Description

We were missing some schema for dockerfile.v0 and test cases for build args in both dockerfile.v0 and container.v1. Once this merges in the schema needs to be published to schema store as well.

Fixes #4864

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
  • No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
  • No
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • Yes
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
      • No
  • No
• Does the change make any security assumptions or guarantees?
  • Yes
    • If yes, have you done a threat model and had a security review?
      • Yes
      • No
  • No
• Does the change require an update in our Aspire docs?
  • Yes
    • Link to aspire-docs issue:
  • No

Microsoft Reviewers: Open in CodeFlow

[davidfowl]

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[mitchdenny]

/azp run

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