Wifi CTS: call WifiManager#reconnect() before asserting that Wifi is connected

To reduce flake, for the tests that need Wifi to
be connected, call WifiManager#reconnect() during
setup in case the previous test disconnected
from Wifi.

Also, when re-enabling a network, also attempt
to connect i.e.
WifiManager.enableNetwork(netId, attemptConnect=true)

Bug: 156712766
Test: atest CtsWifiTestCases
Change-Id: I93684a9b128a7549402ae69ee625ab42a822f890
6 files changed