Add explicit dep on framework-wifi.impl

android_robolectric_test is having some implicit deps removed
from it, so add in what we depend on directly.

Bug: 157451444
Bug: 161767237
Test: m RunSettingsRoboTests
Merged-In: I800b434c8049121db115cff87d51e164e4529999
Change-Id: I847cbeaab7aab6e3cb109df7cafd8a63d63c6acb