Implement the prepare_bazel_test_env script am: 2178bb2de9 am: 8eb6bb443e am: 0fa3de4e84

Original change: https://android-review.googlesource.com/c/platform/build/pesto/+/1677135

Change-Id: Ie548a44bf878663486987ef8917df137563278b5
tree: 1f4fb1e246017932b2da3d2fa21066b184195803
  1. experiments/
  2. OWNERS