Refactor setCurrentProxyScriptUrl to a void method

setCurrentProxyScriptUrl is used by ProxyTracker which is
included in connectivity service mainline module. To make
this method @SystemApi in follow-up patch, change this
from a boolean method to a void method. Moving the send or
not send broadcast logic to caller because it can know
whether it needs to send a broadcast or not.

Bug: 177035719
Test: FrameworksNetTests
Change-Id: I7c0fd20bb449463a65952cfa9fb8a42310da079c
diff --git a/services/core/java/com/android/server/connectivity/ProxyTracker.java b/services/core/java/com/android/server/connectivity/ProxyTracker.java
index d83ff83..b618d2b 100644
--- a/services/core/java/com/android/server/connectivity/ProxyTracker.java
+++ b/services/core/java/com/android/server/connectivity/ProxyTracker.java
@@ -226,9 +226,9 @@
         final ProxyInfo defaultProxy = getDefaultProxy();
         final ProxyInfo proxyInfo = null != defaultProxy ?
                 defaultProxy : ProxyInfo.buildDirectProxy("", 0, Collections.emptyList());
+        mPacProxyInstaller.setCurrentProxyScriptUrl(proxyInfo);
 
-        if (mPacProxyInstaller.setCurrentProxyScriptUrl(proxyInfo)
-                == PacProxyInstaller.DONT_SEND_BROADCAST) {
+        if (!shouldSendBroadcast(proxyInfo)) {
             return;
         }
         if (DBG) Log.d(TAG, "sending Proxy Broadcast for " + proxyInfo);
@@ -244,6 +244,13 @@
         }
     }
 
+    private boolean shouldSendBroadcast(ProxyInfo proxy) {
+        if (Uri.EMPTY.equals(proxy.getPacFileUrl())) return false;
+        if (proxy.getPacFileUrl().equals(proxy.getPacFileUrl())
+                && (proxy.getPort() > 0)) return true;
+        return true;
+    }
+
     /**
      * Sets the global proxy in memory. Also writes the values to the global settings of the device.
      *