Cherry-pick "Support Python 3.9 in ACTS framework" to rvc-dev am: a39eeb59ec

Original change: https://googleplex-android-review.googlesource.com/c/platform/tools/test/connectivity/+/15464706

Change-Id: I37a9576ecef48d497f99956724af14f35f78d259
tree: 9fd1eff6ddf117db74f03853fc7c16ffdd8c4957
  1. acts/
  2. tools/
  3. wts-acts/
  4. Android.mk
  5. OWNERS
  6. PREUPLOAD.cfg