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
Bug: 167568930
Test: m RunSettingsRoboTests
Exempt-From-Owner-Approval:‌ ‌Cherry-pick
Merged-In: I847cbeaab7aab6e3cb109df7cafd8a63d63c6acb
Change-Id: I847cbeaab7aab6e3cb109df7cafd8a63d63c6acb