Add TEST_MAPPING to run CtsHostsideNetworkTests in presubmit.

We already run these tests when platform code affecting these tests
change. Now enabling these too to also run when these tests are being
changed.

Fixes: 154344933
Test: atest --test-mapping packages/modules/Connectivity/tests/cts/hostside
Change-Id: Ie3ea67670ccd028815936d30189146c25ba87e28
diff --git a/tests/cts/hostside/TEST_MAPPING b/tests/cts/hostside/TEST_MAPPING
new file mode 100644
index 0000000..02d2d6e
--- /dev/null
+++ b/tests/cts/hostside/TEST_MAPPING
@@ -0,0 +1,18 @@
+{
+  "presubmit": [
+    {
+      "name": "CtsHostsideNetworkTests",
+      "options": [
+        {
+          "include-filter": "com.android.cts.net.HostsideRestrictBackgroundNetworkTests"
+        },
+        {
+          "exclude-annotation": "androidx.test.filters.FlakyTest"
+        },
+        {
+          "exclude-annotation": "android.platform.test.annotations.FlakyTest"
+        }
+      ]
+    }
+  ]
+}
\ No newline at end of file