Dockerfile apex build command fails
**Describe the bug**

The Dockerfile contains the following command to build apex

```
# TODO: Remove once this Apex commit (2/24/23) is included in PyTorch
# container
RUN git clone https://github.com/NVIDIA/apex.git && \
  cd apex && \
  git checkout 57057e2fcf1c084c0fcc818f55c0ff6ea1b24ae2 && \
  pip3 install -v --disable-pip-version-check --no-cache-dir --global-option="--cpp_ext" --global-option="--cuda_ext" --global-option="--fast_layer_norm" --global-option="--distributed_adam" --global-option="--deprecated_fused_adam" ./
```
But this fails due to https://github.com/NVIDIA/apex/issues/1636

I had to follow the suggestions in the apex issue, i.e. add the following lines on the top of `apex/contrib/layer_norm/ln.h`

```
include <stdint.h>
include <stdio.h>
```