[AI-FSSDK] (DO NOT REVIEW) [FSSDK-12262] Exclude CMAB from UserProfileService

[jaeopt]

Summary

CMAB experiments should not use the User Profile Service (UPS) for sticky bucketing. CMAB decisions are managed by the CMAB service with its own caching mechanism, so UPS should be bypassed for these experiments.

Changes

• Skip UPS lookup (stored variation check) for CMAB experiments in the decision service
• Skip UPS save (variation persistence) after CMAB decisions are made
• Add decision reason when UPS is skipped for CMAB experiments

Jira Ticket

FSSDK-12262

Testing

Verified with unit tests.