Enable/disable WifiConnectivityManager at runtime

Add support to turn on and off WifiConnectivityManager at
runtime.

Bug: 27968625
Change-Id: I57d3604bfb2a4e816fb16f6389f7cbaa2460c24b

wifi/java/android/net/wifi/IWifiManager.aidl

@@ -152,6 +152,8 @@ interface IWifiManager
     boolean enableAutoJoinWhenAssociated(boolean enabled);
     boolean getEnableAutoJoinWhenAssociated();
 
+    void enableWifiConnectivityManager(boolean enabled);
+
     WifiConnectionStatistics getConnectionStatistics();
 
     void disableEphemeralNetwork(String SSID);

wifi/java/android/net/wifi/WifiManager.java

@@ -2719,4 +2719,16 @@ public class WifiManager {
             throw e.rethrowFromSystemServer();
         }
     }
+
+    /**
+     * Enable/disable WifiConnectivityManager
+     * @hide
+     */
+    public void enableWifiConnectivityManager(boolean enabled) {
+        try {
+            mService.enableWifiConnectivityManager(enabled);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
 }