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

See go/jetpack-test-android-migration

Test: atest TestablesTests NetworkStackTests FrameworksServicesTests SystemUITests FrameworksUiServicesTests ExtServicesUnitTests
Exempt-From-Owner-Approval: already reviewed
Change-Id: I083fcdaa71b503535aa2b3c257740f3ecf055373
Merged-In: Ib04d80954bd8536914d88c66b28e6632e60a6245
diff --git a/services/tests/servicestests/src/com/android/server/backup/TrampolineTest.java b/services/tests/servicestests/src/com/android/server/backup/TrampolineTest.java
index bbd999b..79eba68 100644
--- a/services/tests/servicestests/src/com/android/server/backup/TrampolineTest.java
+++ b/services/tests/servicestests/src/com/android/server/backup/TrampolineTest.java
@@ -43,8 +43,9 @@
 import android.os.RemoteException;
 import android.os.UserHandle;
 import android.platform.test.annotations.Presubmit;
-import android.support.test.filters.SmallTest;
-import android.support.test.runner.AndroidJUnit4;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
 
 import org.junit.Before;
 import org.junit.Test;