[AI-FSSDK] [FSSDK-12337] Add ExperimentTypes constants for type field

- Add ExperimentTypes enum in helpers/enums.py with AB, MAB, CMAB, FEATURE_ROLLOUT
- Use ExperimentTypes.FEATURE_ROLLOUT constant in config parsing instead of raw string

Author: FarhanAnjum-opti

optimizely/helpers/enums.py

@@ -102,6 +102,13 @@ class DecisionSources:
     HOLDOUT: Final = 'holdout'
 
 
+class ExperimentTypes:
+    AB: Final = 'a/b'
+    MAB: Final = 'mab'
+    CMAB: Final = 'cmab'
+    FEATURE_ROLLOUT: Final = 'feature_rollout'
+
+
 class Errors:
     INVALID_ATTRIBUTE: Final = 'Provided attribute is not in datafile.'
     INVALID_ATTRIBUTE_FORMAT: Final = 'Attributes provided are in an invalid format.'

optimizely/project_config.py

@@ -237,7 +237,7 @@ def __init__(self, datafile: str | bytes, logger: Logger, error_handler: Any):
             everyone_else_variation = self._get_everyone_else_variation(feature)
             if everyone_else_variation is not None:
                 for experiment in rules:
-                    if getattr(experiment, 'type', None) == 'feature_rollout':
+                    if getattr(experiment, 'type', None) == enums.ExperimentTypes.FEATURE_ROLLOUT:
                         experiment.variations.append(everyone_else_variation)
                         experiment.trafficAllocation.append({
                             'entityId': everyone_else_variation['id'],