Tidy up MockWebServer usage

Delay creation of MockWebServer until setUp() and
add shutdown logic in one case.

Bug: 29820565
Change-Id: Iea43f8692b8425d05405a8fe86382d6d12197b2d

core/tests/coretests/src/android/app/DownloadManagerBaseTest.java

@@ -245,6 +245,12 @@ public class DownloadManagerBaseTest extends InstrumentationTestCase {
         // Note: callers overriding this should call mServer.play() with the desired port #
     }
 
+    @Override
+    public void tearDown() throws Exception {
+        mServer.shutdown();
+        super.tearDown();
+    }
+
     /**
      * Helper to build a response from the MockWebServer with no body.
      *

core/tests/coretests/src/android/net/http/CookiesTest.java

@@ -36,7 +36,13 @@ import org.apache.http.impl.client.DefaultHttpClient;
 
 public final class CookiesTest extends TestCase {
 
-    private MockWebServer server = new MockWebServer();
+    private MockWebServer server;
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+        server = new MockWebServer();
+    }
 
     @Override protected void tearDown() throws Exception {
         server.shutdown();

core/tests/coretests/src/android/net/http/DefaultHttpClientTest.java

@@ -41,7 +41,13 @@ import org.apache.http.message.BasicHeader;
  */
 public final class DefaultHttpClientTest extends TestCase {
 
-    private MockWebServer server = new MockWebServer();
+    private MockWebServer server;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        server = new MockWebServer();
+    }
 
     @Override protected void tearDown() throws Exception {
         server.shutdown();