Add WifiShortAggTimeout and WifiNoAggTimeout experiments.

- WifiShortAggTimeout: tell mac80211 to use a very short aggregation
  timeout, which ought to increase occurrences of b/23786055 (maybe useful
  for automated tests; to trigger the problem, set the short timeout and
  then ping once per second on an otherwise idle link, with nonzero background
  interference present).

- WifiNoAggTimeout: tell mac80211 to disable aggregation timeout, which seems
  to solve b/23786055.  (Probably this should be the default someday.)

Change-Id: I810160e8e3f284e7fb359a00f10fa5b15cef85d0
2 files changed