Add retries for WifiManager#connect

Connect can error with BUSY if the framework is busy when connect is
called. Add retries so that if this happens, the connection can succeed
after the framework stops being busy.

Also log the level of scan results when several configurations are
available, and clarify the legacy broadcast assert.

Bug: 188077861
Test: atest CtsNetTestCases
Change-Id: I99ce72bd2604489cb419ea9984643b6985728461
1 file changed