[FE] Migrate to shared FF

There is already a FF for this feature. Updating the FE to use the same FF as the BE

[FF] `secret_detection_validity_checks_refresh_... (#552306)

- validity_refresh
+ secretDetectionValidityChecksRefreshToken

Implementation Plan

1. Remove FF usages in the code
2. Disable FF in all environments

/chatops run feature set validity_refresh false

3. Remove FF in all environments
   • Close issue [FF] `validity_refresh` roll out (#556937 - closed)

/chatops run feature delete <feature-flag-name> --dev --pre --staging --staging-ref --production