Add cmab_flag to expected_config featuresMap

The /v1/config API response for revision 139 includes cmab_flag in the
featuresMap, so the expected_config needs to include it as well.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Mat001

tests/acceptance/test_acceptance/test_config.py

@@ -132,6 +132,68 @@
                 }
             }
         },
+        "cmab_flag": {
+            "id": "496419",
+            "key": "cmab_flag",
+            "experimentRules": [
+                {
+                    "id": "9300002877087",
+                    "key": "cmab-rule_1",
+                    "audiences": "\\"Audience1\\"",
+                    "variationsMap": {
+                        "off": {
+                            "id": "1579277",
+                            "key": "off",
+                            "featureEnabled": false,
+                            "variablesMap": {}
+                        },
+                        "on": {
+                            "id": "1579278",
+                            "key": "on",
+                            "featureEnabled": true,
+                            "variablesMap": {}
+                        }
+                    }
+                }
+            ],
+            "deliveryRules": [
+                {
+                    "id": "default-rollout-496419-16935023792",
+                    "key": "default-rollout-496419-16935023792",
+                    "audiences": "",
+                    "variationsMap": {
+                        "off": {
+                            "id": "1579277",
+                            "key": "off",
+                            "featureEnabled": false,
+                            "variablesMap": {}
+                        }
+                    }
+                }
+            ],
+            "variablesMap": {},
+            "experimentsMap": {
+                "cmab-rule_1": {
+                    "id": "9300002877087",
+                    "key": "cmab-rule_1",
+                    "audiences": "\\"Audience1\\"",
+                    "variationsMap": {
+                        "off": {
+                            "id": "1579277",
+                            "key": "off",
+                            "featureEnabled": false,
+                            "variablesMap": {}
+                        },
+                        "on": {
+                            "id": "1579278",
+                            "key": "on",
+                            "featureEnabled": true,
+                            "variablesMap": {}
+                        }
+                    }
+                }
+            }
+        },
         "feature_1": {
             "id": "16925981047",
             "key": "feature_1",