wifi: Update API java to match new design

Update the java doc to match new behavior as below:

ClientControlByUserEnabled (true)
-> disconnect new/unknown MAC + Callback;
New clients will need to attempt again and
will be allowed/disallowed based on user action
in the previous callback.

ClientControlByUserEnabled (false=default)
-> allow new/unknown MAC + Callback;
New clients will not disconnect unless the user
chooses to disallow the client by adding to the blocklist.

Bug: 159582750
Test: atest FrameworksWifiTests
Test: make docs frameworks/base/wifi/
Change-Id: I64a85db0a28342003f902c50f81531b2218a6252