Migrate packages/apps/Settings to androidx.test

See go/jetpack-test-android-migration

Test: make checkbuild
Change-Id: If67b124188fd4e303154eb11263d03abfb3718c6
diff --git a/tests/uitests/AndroidTest.xml b/tests/uitests/AndroidTest.xml
index 4162207..50c6a75 100644
--- a/tests/uitests/AndroidTest.xml
+++ b/tests/uitests/AndroidTest.xml
@@ -24,7 +24,7 @@
     <option name="test-tag" value="SettingsUITests" />
     <test class="com.android.tradefed.testtype.AndroidJUnitTest" >
         <option name="package" value="com.android.settings.ui" />
-        <option name="runner" value="android.support.test.runner.AndroidJUnitRunner" />
+        <option name="runner" value="androidx.test.runner.AndroidJUnitRunner" />
         <option name="hidden-api-checks" value="false"/>
     </test>
 </configuration>