DynamicPartitionsControl: Add Virtual A/B feature flag.

Test: unittest
Bug: 138816109
Change-Id: I7ae65ba0bf36a6ca5085bc4ec2c46245288b4703
diff --git a/boot_control_android_unittest.cc b/boot_control_android_unittest.cc
index 6f02a07..3b92191 100644
--- a/boot_control_android_unittest.cc
+++ b/boot_control_android_unittest.cc
@@ -62,6 +62,8 @@
 
     ON_CALL(dynamicControl(), GetDynamicPartitionsFeatureFlag())
         .WillByDefault(Return(FeatureFlag(FeatureFlag::Value::LAUNCH)));
+    ON_CALL(dynamicControl(), GetVirtualAbFeatureFlag())
+        .WillByDefault(Return(FeatureFlag(FeatureFlag::Value::NONE)));
     ON_CALL(dynamicControl(), DeviceExists(_)).WillByDefault(Return(true));
     ON_CALL(dynamicControl(), GetDeviceDir(_))
         .WillByDefault(Invoke([](auto path) {