Merge pull request #12013 from tfboyd/grappler_off_branch

Make layout optimizer_test manual due to Grappler being off in the r1.3 branch.

tensorflow/python/BUILD

@@ -3927,6 +3927,7 @@ cuda_py_test(
         "//third_party/py/numpy",
         "//tensorflow/core:protos_all_py",
     ],
+    tags = ["manual"],
 )
 
 py_library(