Fix instance normalization scale initializer
Fix instance normalization scale initializer

As per [previous discussion](https://github.com/tensorflow/examples/commit/f28b124a2aabdc58a66f5f12904824fd110599a2#r34756231), the scale parameter of the instance normalization should be initialized with mean `1.0` instead of `0.0`.
tensorflow/examples,tensorflow/examples,tensorflow/examples,tensorflow/examples,tensorflow/examples,tensorflow/examples,tensorflow/examples,tensorflow/examples,tensorflow/examples