Enable CFStream with environment variable
diff --git a/BUILD b/BUILD
index 81390dd..433ae27 100644
--- a/BUILD
+++ b/BUILD
@@ -1010,6 +1010,7 @@
         "src/core/lib/iomgr/cfstream_handle.cc",
         "src/core/lib/iomgr/endpoint_cfstream.cc",
         "src/core/lib/iomgr/error_cfstream.cc",
+        "src/core/lib/iomgr/iomgr_posix_cfstream.cc",
         "src/core/lib/iomgr/tcp_client_cfstream.cc",
     ],
     hdrs = [