Revert "Connect FeatureFlags with FeatureFlagsService."

Revert submission 23727772-b279054964-flag-api-udc-qpr-dev

Reason for revert: b/290929382

Reverted changes: /q/submissionid:23727772-b279054964-flag-api-udc-qpr-dev

Change-Id: I5ebfe5ac5ac518f33c4bd3beaa4cd018b43242cf
12 files changed