Move environment root and fix envtest logs

Change-Id: I55fac9be0c1626c5f874cd6aa464a4853a1442f1
Reviewed-on: https://pigweed-review.googlesource.com/c/infra/recipes/+/14481
Reviewed-by: Oliver Newman <olivernewman@google.com>
Commit-Queue: Rob Mohr <mohrr@google.com>