Update multi-client wifi scanner test class.

Utilize asserts module instead of raw assert.
Apply pep8 style changes.
Add attenuator control so it runs in new wifi test setup.

Bug=29182983

Change-Id: If0ed0762d0a46a03d8b7b07323f908204d641423
1 file changed
tree: 3eaad0451423fc95563e3a58ee0b3a07a2ec482c
  1. acts/