Restrict 'backoff' version for Python<3.7

Bug: 285435335
Test: local
Change-Id: I12cb01cd7c785c84f76c8ef8806b8f950aebaa2d
1 file changed
tree: 379bc75d90b013b9ff42dc3c61eca6143a397db7
  1. acts/
  2. acts_tests/
  3. tools/
  4. wts-acts/
  5. Android.mk
  6. LICENSE
  7. OWNERS
  8. PREUPLOAD.cfg