Send ConnDiags event before revalidating network in CS.

This change updates ConnectivityService to notify the
ConnectivityDiagnosticsHandler of app-reported connectivity before
attempting to revalidate the network. This change forces an ordering on
Connectivity Diagnostics events in the case that the reported
connectivity does not match the known connectivity for the network -
this leads to the network being revalidated and the
ConnectivityDiagnostics event onConnectivityReportAvailable. Passing the
onNetworkConnectivityReported event to the
ConnectivityDiagnosticsHandler first ensures that it is passed to
callbacks before any potential ConnectivityReports are.

Bug: 159718782
Test: android.net.cts.ConnectivityDiagnosticsManagerTest
Change-Id: Ic7bc7138c54c47bbfdf56af5811709fde66f8606

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

@@ -4315,9 +4315,11 @@ public class ConnectivityService extends IConnectivityManager.Stub
         enforceInternetPermission();
         final int uid = Binder.getCallingUid();
         final int connectivityInfo = encodeBool(hasConnectivity);
-        mHandler.sendMessage(
-                mHandler.obtainMessage(EVENT_REVALIDATE_NETWORK, uid, connectivityInfo, network));
 
+        // Handle ConnectivityDiagnostics event before attempting to revalidate the network. This
+        // forces an ordering of ConnectivityDiagnostics events in the case where hasConnectivity
+        // does not match the known connectivity of the network - this causes NetworkMonitor to
+        // revalidate the network and generate a ConnectivityDiagnostics ConnectivityReport event.
         final NetworkAgentInfo nai;
         if (network == null) {
             nai = getDefaultNetwork();
@@ -4330,6 +4332,9 @@ public class ConnectivityService extends IConnectivityManager.Stub
                             ConnectivityDiagnosticsHandler.EVENT_NETWORK_CONNECTIVITY_REPORTED,
                             connectivityInfo, 0, nai));
         }
+
+        mHandler.sendMessage(
+                mHandler.obtainMessage(EVENT_REVALIDATE_NETWORK, uid, connectivityInfo, network));
     }
 
     private void handleReportNetworkConnectivity(