Libcore: Hardcode http system properties

Hardcode properties to default (non-existent).

Allows to compile-time initialize:
* android.net.Network
* com.android.okhttp.ConfigAwareConnectionPool

Bug: 27265238
Bug: 28174137

(cherry picked from commit 31bf68cd51e292412bb2c511c72fee644fd9dc9e)

Change-Id: I3d2e278b3055c234af8fc3a09a3639f42548bde7
diff --git a/libart/src/main/java/java/lang/AndroidHardcodedSystemProperties.java b/libart/src/main/java/java/lang/AndroidHardcodedSystemProperties.java
index db46f74..6c203b3 100644
--- a/libart/src/main/java/java/lang/AndroidHardcodedSystemProperties.java
+++ b/libart/src/main/java/java/lang/AndroidHardcodedSystemProperties.java
@@ -85,6 +85,11 @@
         // Hardcode "sun.io.useCanonCaches" to use the default (on). b/28174137
         { "sun.io.useCanonCaches", null },
         { "sun.io.useCanonPrefixCache", null },
+
+        // Hardcode some http properties to use the default. b/28174137
+        { "http.keepAlive", null },
+        { "http.keepAliveDuration", null },
+        { "http.maxConnections", null },
     };
 }