connectToWifi needs to clear the wifi networks blacklist before calling
reconnect(), otherwise wifi may not reconnect if the previous network
was blacklisted.
disconnectFromWifi should not wait for a onLost callback if wifi was
already disconnected.
Test: atest CtsNetTestCasesLatestSdk:ConnectivityManagerTest
Test: atest CtsNetApi23TestCases
Bug: 150949391
Original-Change: https://android-review.googlesource.com/1322428
Merged-In: I244b91bdd8708694fce9f10d92b8b6646d28188f
Change-Id: I244b91bdd8708694fce9f10d92b8b6646d28188f
d1c80d7e20