Update Save Search body (CRASM-2604)

[hawkishpolicy]

🗣 Description

• a prior issue's(Elastic Search sort CRASM-2758) solution reset the casing of sort field and sort direction from snake case to camel case.
• need to update the save search call to use the correct casing for sort field and sort direction.

💭 Motivation and context

• Closes CRASM-2604

🧪 Testing

• tested locally

📷 Screenshots (if appropriate)

Screen.Recording.2025-07-01.at.1.35.25.PM.mov

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All new and existing tests pass.
• Bump major, minor, patch, pre-release, and/or build versions as appropriate via the bump_version script if this repository is versioned and the changes in this PR warrant a version bump.
• Create a pre-release (necessary if and only if the pre-release version was bumped).

✅ Pre-merge checklist

• Revert dependencies to default branches.
• Finalize version.

✅ Post-merge checklist

• Create a release (necessary if and only if the version was bumped).

[cduhn17]

LGTM - review done in group

[chrtorres]

LGTM