WifiLastResortWatchdog trigger logic

Implemented trigger condition logic that is checked after a failure is
counted. The condition takes into account: failure counts, wifi
connected state, past connections to saved networks and whether the
watchdog has fired since the wifi environment changed.

Please note: This change only implements the logic for deciding when to
trigger, not the trigger itself.

BUG=27856709

Change-Id: I91ad6127a72ca24c72a5520348c4fff83f16b559
3 files changed
tree: 037d8bb8fadca65575a7783f55ed7b7eb17f17f1
  1. service/
  2. tests/