Increase tf_preparer_incremental_setup roll out percentage to 10%

Test: Presubmit
Change-Id: Icbacbcd0446e12cdf5b65390a1556102aa1e10e1
diff --git a/atest/rollout_control.py b/atest/rollout_control.py
index 2a89f5b..617e92c 100644
--- a/atest/rollout_control.py
+++ b/atest/rollout_control.py
@@ -203,7 +203,7 @@
 
 tf_preparer_incremental_setup = RolloutControlledFeature(
     name='TradeFed preparer incremental setup',
-    rollout_percentage=0,
+    rollout_percentage=10,
     env_control_flag='TF_PREPARER_INCREMENTAL_SETUP',
     feature_id=3,
     print_message=(