[8.12] [Security Solution] Enable the feature flag for JSON diffing in prebuilt rules (#173368) (#173822)

# Backport

This will backport the following commits from `main` to `8.12`:
- [[Security Solution] Enable the feature flag for JSON diffing in
prebuilt rules (#173368)](https://github.com/elastic/kibana/pull/173368)

<!--- Backport version: 8.9.7 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Nikita
Indik","email":"nikita.indik@elastic.co"},"sourceCommit":{"committedDate":"2023-12-21T11:39:16Z","message":"[Security
Solution] Enable the feature flag for JSON diffing in prebuilt rules
(#173368)\n\n**Ticket:**
https://github.com/elastic/kibana/issues/169160\r\n\r\n##
Summary\r\n\r\nSets the `jsonPrebuiltRulesDiffingEnabled` to `true` to
enable the new\r\n\"Updates\" tab in prebuilt rules flyout.\r\n\r\n###
IMPORTANT: Merge only once acceptance and exploratory testing
are\r\npassed!\r\n\r\n<img width=\"1178\" alt=\"Scherm­afbeelding
2023-12-13 om 17 37
07\"\r\nsrc=\"9e07e069-595f-49a6-98c2-d2ed4aa3f977\">\r\n\r\nCo-authored-by:
Georgii Gorbachev
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Solution] Enable the feature flag for JSON diffing in prebuilt rules
(#173368)\n\n**Ticket:**
https://github.com/elastic/kibana/issues/169160\r\n\r\n##
Summary\r\n\r\nSets the `jsonPrebuiltRulesDiffingEnabled` to `true` to
enable the new\r\n\"Updates\" tab in prebuilt rules flyout.\r\n\r\n###
IMPORTANT: Merge only once acceptance and exploratory testing
are\r\npassed!\r\n\r\n<img width=\"1178\" alt=\"Scherm­afbeelding
2023-12-13 om 17 37
07\"\r\nsrc=\"9e07e069-595f-49a6-98c2-d2ed4aa3f977\">\r\n\r\nCo-authored-by:
Georgii Gorbachev
<georgii.gorbachev@elastic.co>","sha":"d7b99a587799e34c9534e4ba793aad65b4f78d55"}},"sourceBranch":"main","suggestedTargetBranches":["8.12"],"targetPullRequestStates":[{"branch":"8.12","label":"v8.12.0","labelRegex":"^v(\\d+).(\\d+).\\d+$","isSourceBranch":false,"state":"NOT_CREATED"},{"branch":"main","label":"v8.13.0","labelRegex":"^v8.13.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/173368","number":173368,"mergeCommit":{"message":"[Security
Solution] Enable the feature flag for JSON diffing in prebuilt rules
(#173368)\n\n**Ticket:**
https://github.com/elastic/kibana/issues/169160\r\n\r\n##
Summary\r\n\r\nSets the `jsonPrebuiltRulesDiffingEnabled` to `true` to
enable the new\r\n\"Updates\" tab in prebuilt rules flyout.\r\n\r\n###
IMPORTANT: Merge only once acceptance and exploratory testing
are\r\npassed!\r\n\r\n<img width=\"1178\" alt=\"Scherm­afbeelding
2023-12-13 om 17 37
07\"\r\nsrc=\"9e07e069-595f-49a6-98c2-d2ed4aa3f977\">\r\n\r\nCo-authored-by:
Georgii Gorbachev
<georgii.gorbachev@elastic.co>","sha":"d7b99a587799e34c9534e4ba793aad65b4f78d55"}}]}]
BACKPORT-->

Co-authored-by: Nikita Indik <nikita.indik@elastic.co>

x-pack/plugins/security_solution/common/experimental_features.ts

@@ -162,7 +162,7 @@ export const allowedExperimentalValues = Object.freeze({
    * This tab shows the JSON diff between the installed prebuilt rule
    * version and the latest available version.
    */
-  jsonPrebuiltRulesDiffingEnabled: false,
+  jsonPrebuiltRulesDiffingEnabled: true,
 });
 
 type ExperimentalConfigKeys = Array<keyof ExperimentalFeatures>;