WifiServiceImplTest: Fix errorprone errors

Forgot to add @Test for new unit tests.
Also, fixed some bugs in these tests

Bug: 142518824
Test: Wifi related erorrprone error no longer seen.
Change-Id: I9522f9fd3583e78ff24d0e83c220380291bc21b6
Test: atest com.android.server.wifi
(cherry-picked from 10c9371a187bb922eac7c97b0d04e9b972ac9966)
1 file changed
tree: a8504fa9ad310eff5033c0edd5a594859f184647
  1. service/
  2. PREUPLOAD.cfg