Move the NetworkStack tests to unit/ to add an integration test.

Test: m
Bug: 133389827
(cherry pick from aosp/960932)
Merged-In: I7aeab47b31429b1f9a42f9b170aeba238c133950
Change-Id: Ie455b7a6a950cb5e34841efc3738c11fe1fd12f0

packages/NetworkStack/tests/unit/src/com/android/server/connectivity/NetworkMonitorTest.java

@@ -297,6 +297,7 @@ public class NetworkMonitorTest {
         setOtherFallbackUrls(TEST_OTHER_FALLBACK_URL);
         setFallbackSpecs(null); // Test with no fallback spec by default
         when(mRandom.nextInt()).thenReturn(0);
+
         // DNS probe timeout should not be defined more than half of HANDLER_TIMEOUT_MS. Otherwise,
         // it will fail the test because of timeout expired for querying AAAA and A sequentially.
         when(mResources.getInteger(eq(R.integer.config_captive_portal_dns_probe_timeout)))