Migrate packages/apps/Contacts to androidx.test

See go/jetpack-test-android-migration

Test: make checkbuild
Change-Id: I0abad7618ac496561f6fb07da2590c79f82a2024
diff --git a/tests/AndroidManifest.xml b/tests/AndroidManifest.xml
index e3d9820..9f3d5d5 100644
--- a/tests/AndroidManifest.xml
+++ b/tests/AndroidManifest.xml
@@ -90,7 +90,7 @@
         <service android:name=".PhoneNumberTestService" />
     </application>
 
-    <instrumentation android:name="android.support.test.runner.AndroidJUnitRunner"
+    <instrumentation android:name="androidx.test.runner.AndroidJUnitRunner"
         android:targetPackage="com.android.contacts"
         android:label="Contacts app tests">
     </instrumentation>