Migrate frameworks/opt/net/ethernet to androidx.test

See go/jetpack-test-android-migration

Test: compile
Change-Id: I20fc49dd2487af2245f060454e7f32f5e9145a9c
diff --git a/tests/ethernet/Android.bp b/tests/ethernet/Android.bp
index 8c5df21..9c776e6 100644
--- a/tests/ethernet/Android.bp
+++ b/tests/ethernet/Android.bp
@@ -27,7 +27,7 @@
     ],
 
     static_libs: [
-        "android-support-test",
+        "androidx.test.rules",
         "ethernet-service",
     ],
 }