Use a single socket to communicate with supplicant

This helps to prepare for future updates from external sources.

Bug: 9298955

Change-Id: I4c63ad5fc1ea3564aab38cfce955de19bad75c0c
(cherry picked from commit fb40801ed8c217ae01082fb1cbd0c30bbf5532ac)

core/jni/android_net_NetUtils.cpp

@@ -141,7 +141,7 @@ static jboolean android_net_utils_runDhcpCommon(JNIEnv* env, jobject clazz, jstr
                 dns, server, &lease, vendorInfo, domains, mtu);
     }
     if (result != 0) {
-        ALOGD("dhcp_do_request failed");
+        ALOGD("dhcp_do_request failed : %s (%s)", nameStr, renew ? "renew" : "new");
     }
 
     env->ReleaseStringUTFChars(ifname, nameStr);