Fix LinkPropertiesTest on *-user builds

Mark CtsNetTestCases test app as debuggable to let it run correctly on
*-user build targets.

Test: atest CtsnetTestCases:LinkPropertiesTest
Bug: 229813087
Change-Id: I21435cd6cb5c43074eef95e8896c02652ffea216
diff --git a/tests/cts/net/AndroidManifest.xml b/tests/cts/net/AndroidManifest.xml
index 3b47100..6b5bb93 100644
--- a/tests/cts/net/AndroidManifest.xml
+++ b/tests/cts/net/AndroidManifest.xml
@@ -44,7 +44,8 @@
              android.permission.MANAGE_TEST_NETWORKS
     -->
 
-    <application android:usesCleartextTraffic="true">
+    <application android:debuggable="true"
+                 android:usesCleartextTraffic="true">
         <uses-library android:name="android.test.runner" />
         <uses-library android:name="org.apache.http.legacy" android:required="false" />
     </application>