ConnectivityService: detach the logic of global proxy.

The current implementation of global proxy is dead,
and it will be removed completely in separate changes.

Change-Id: I54f6b3960f761483d28d808e99db4c71c9c0348d

Author: Chia-chi Yeh

services/java/com/android/server/ConnectivityService.java

@@ -2550,9 +2550,7 @@ private void handleInetConditionHoldEnd(int netType, int sequence) {
     }
 
     public synchronized ProxyProperties getProxy() {
-        if (mGlobalProxy != null) return mGlobalProxy;
-        if (mDefaultProxy != null) return mDefaultProxy;
-        return null;
+        return mDefaultProxy;
     }
 
     public void setGlobalProxy(ProxyProperties proxyProperties) {
@@ -2583,7 +2581,7 @@ public void setGlobalProxy(ProxyProperties proxyProperties) {
         if (mGlobalProxy == null) {
             proxyProperties = mDefaultProxy;
         }
-        sendProxyBroadcast(proxyProperties);
+        //sendProxyBroadcast(proxyProperties);
     }
 
     private void loadGlobalProxy() {
@@ -2619,9 +2617,6 @@ private void handleApplyDefaultProxy(int type) {
             }
         }
         if (VDBG) log("changing default proxy to " + proxy);
-
-        // global trumps default, if set, ignore this.
-        if (mGlobalProxy != null) return;
         sendProxyBroadcast(proxy);
     }