Fix WifiTrackerTest stopTrackingShouldRemove . . .

Fix a race condition in
com.android.settingslib.wifi.WifiTrackerTest#stopTrackingShouldRemoveWifiListenerCallbacks

Bug: 70171301
Test: runtest --path frameworks/base/packages/SettingsLib/tests/integ/src/com/android/settingslib/wifi/WifiTrackerTest.java
Test: repeat the test lots of times - failure rate was < 1% before fix.
Change-Id: Ib9c9cb3dbfb3413484530be5fc0c2e20fd470b97
1 file changed