Merge changes from topic 'am-febb6164619c46f681eb6dc8a6c58e06'

* changes:
  Test passing null cert/keys to WifiEnterpriseConfig am: 88b3c589ad am: cb79016b16 am: 3bac61ac86 am: 96c87f7a9b
  Account for null client certificate am: 1ca57a1d10 am: 4ad314b463 am: 25eff7731a am: b35b219516
  Add a client chain to WifiEnterpriseConfig am: 291ddaef78 am: cd463ff269 am: 80b5793645 am: 9c9d4f6f6d  -s ours