Provide zone args for acloud create to help TF host allocating resources.

Bug: 160548800
Test: acloud-dev create_cf --zone us-central1-c --branch aosp-master \
--build-target aosp_cf_x86_phone-userdebug
acloud-py3-dev create --zone us-central1-b

Change-Id: I3d50f4356c8b08107c34174e6fc77a30521b56a5
diff --git a/public/config_test.py b/public/config_test.py
index 510fb13..88f2899 100644
--- a/public/config_test.py
+++ b/public/config_test.py
@@ -288,6 +288,15 @@
         cfg.OverrideWithArgs(args)
         self.assertEqual(cfg.hw_property, "")
 
+        # test override zone.
+        cfg.zone = "us-central1-f"
+        args = mock.MagicMock()
+        args.which = "create"
+        args.flavor = "phone"
+        args.zone = "us-central1-b"
+        cfg.OverrideWithArgs(args)
+        self.assertEqual(cfg.zone, "us-central1-b")
+
 
 if __name__ == "__main__":
     unittest.main()