Fix HttpResponseCacheTest in anticipation of an OkHttp upgrade.

OkHttp recently changed the behavior of their caching with
commit e74e3f3bf744ef7f4d8ee724a7cf2347e486cfab - it is now
neccessary to close the inputstream (or disconnect the
HttpURLConnection) for a response to be cached.

This change is (effectively) a no-op prior to the upgrade.

The behavior is undefined as to whether closing the
input stream is required for caching. OkHttp's new behavior
is consistent with other HttpURLConnection implementations
tried.

Change-Id: Iaf57371651296ac84850971ef60a9338cead57c0

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

@@ -19,6 +19,7 @@ package android.net.http;
 import com.google.mockwebserver.MockResponse;
 import com.google.mockwebserver.MockWebServer;
 import java.io.File;
+import java.io.InputStream;
 import java.net.CacheRequest;
 import java.net.CacheResponse;
 import java.net.ResponseCache;
@@ -118,7 +119,10 @@ public final class HttpResponseCacheTest extends TestCase {
         server.play();
 
         URLConnection c1 = server.getUrl("/").openConnection();
-        assertEquals('A', c1.getInputStream().read());
+        InputStream inputStream1 = c1.getInputStream();
+        assertEquals('A', inputStream1.read());
+        inputStream1.close();
+
         assertEquals(1, cache.getRequestCount());
         assertEquals(1, cache.getNetworkCount());
         assertEquals(0, cache.getHitCount());