[Security Solution] Integration tests for multi line string field dif…

…f algorithm (elastic#188688)

## Summary

Completes elastic#180159

Switches fields to use the multi line string diff algorithm assigned to
them in the [overarching
ticket](elastic#180159 (comment))

Adds integration tests in accordance to
elastic#188323 for the `upgrade/_review`
API endpoint for the multi line string field diff algorithm.


### Checklist

Delete any items that are not applicable to this PR.

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [x] [Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed


### For maintainers

- [ ] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/calculate_rule_fields_diff.ts

@@ -38,6 +38,7 @@ import type { ThreeVersionsOf } from '../../../../../../../common/api/detection_
 import { MissingVersion } from '../../../../../../../common/api/detection_engine/prebuilt_rules/model/diff/three_way_diff/three_way_diff';
 import { calculateFieldsDiffFor } from './diff_calculation_helpers';
 import {
+  multiLineStringDiffAlgorithm,
   numberDiffAlgorithm,
   scalarArrayDiffAlgorithm,
   simpleDiffAlgorithm,
@@ -176,16 +177,16 @@ const commonFieldsDiffAlgorithms: FieldsDiffAlgorithmsFor<DiffableCommonFields>
   version: numberDiffAlgorithm,
   name: singleLineStringDiffAlgorithm,
   tags: scalarArrayDiffAlgorithm,
-  description: simpleDiffAlgorithm,
+  description: multiLineStringDiffAlgorithm,
   severity: singleLineStringDiffAlgorithm,
   severity_mapping: simpleDiffAlgorithm,
   risk_score: numberDiffAlgorithm,
   risk_score_mapping: simpleDiffAlgorithm,
   references: scalarArrayDiffAlgorithm,
   false_positives: simpleDiffAlgorithm,
   threat: simpleDiffAlgorithm,
-  note: simpleDiffAlgorithm,
-  setup: simpleDiffAlgorithm,
+  note: multiLineStringDiffAlgorithm,
+  setup: multiLineStringDiffAlgorithm,
   related_integrations: simpleDiffAlgorithm,
   required_fields: simpleDiffAlgorithm,
   author: scalarArrayDiffAlgorithm,

x-pack/test/security_solution_api_integration/test_suites/detections_response/rules_management/prebuilt_rules/management/trial_license_complete_tier/index.ts

@@ -19,6 +19,7 @@ export default ({ loadTestFile }: FtrProviderContext): void => {
     loadTestFile(require.resolve('./upgrade_review_prebuilt_rules.number_fields'));
     loadTestFile(require.resolve('./upgrade_review_prebuilt_rules.single_line_string_fields'));
     loadTestFile(require.resolve('./upgrade_review_prebuilt_rules.scalar_array_fields'));
+    loadTestFile(require.resolve('./upgrade_review_prebuilt_rules.multi_line_string_fields'));
     loadTestFile(require.resolve('./upgrade_review_prebuilt_rules.stats'));
   });
 };