xla

706c2039 - Fix stable docker container tag in README (#3512)

Fix stable docker container tag in README (#3512) `gcr.io/tpu-pytorch/xla:r1.11` doesn't exist, use `gcr.io/tpu-pytorch/xla:r1.11_3.7` instead Test plan: ``` docker pull gcr.io/tpu-pytorch/xla:r1.11_3.7 ```