Migrate frameworks/base/tests/testables and its users to androidx.test

See go/jetpack-test-android-migration

This is the internal version of AOSP change aosp/908373

Test: m -j TestablesTests NetworkStackTests FrameworksServicesTests SystemUITests FrameworksUiServicesTests ExtServicesUnitTests WmTests FrameworksCoreTests

Exempt-From-Owner-Approval: automated package name refactoring; already reviewed on AOSP
Change-Id: Ib04d80954bd8536914d88c66b28e6632e60a6245
diff --git a/tests/testables/src/android/testing/TestableInstrumentation.java b/tests/testables/src/android/testing/TestableInstrumentation.java
index c35dc68..ed867c1 100644
--- a/tests/testables/src/android/testing/TestableInstrumentation.java
+++ b/tests/testables/src/android/testing/TestableInstrumentation.java
@@ -19,9 +19,10 @@
 import android.os.Looper;
 import android.os.Message;
 import android.os.TestLooperManager;
-import android.support.test.runner.AndroidJUnitRunner;
 import android.util.Log;
 
+import androidx.test.runner.AndroidJUnitRunner;
+
 import java.util.ArrayList;
 
 /**