Improve the wifi roaming procedure

Current roaming procedure changes the value of attenuator in one step
But this scenario will cause DUT disconnected then reconnect, not roaming.
Improve this procedure by changing the value of attenuator smoothly.

Bug: 116185654
Test: local
Change-Id: I10b247f803264f8f429c78d7ac5acdf2f24f9b2e
1 file changed
tree: 16c2aacd0ca75e50ad9d748ad2171b2839c53e07
  1. acts/
  2. tools/
  3. wts-acts/
  4. Android.mk
  5. PREUPLOAD.cfg