Disable existing wifi connection before connecting hotspot (#90)

Author: lakshyagupta21

share_app/src/main/java/org/odk/share/activities/SendActivity.java

@@ -19,6 +19,7 @@
 import android.widget.Toast;
 
 import org.odk.share.R;
+import org.odk.share.controller.WifiHelper;
 import org.odk.share.controller.WifiHotspotHelper;
 import org.odk.share.events.HotspotEvent;
 import org.odk.share.events.UploadEvent;
@@ -100,6 +101,10 @@ protected void onCreate(Bundle savedInstanceState) {
             Timber.e("Port not available for socket communication");
             finish();
         }
+        WifiHelper wifiHelper = new WifiHelper(this);
+        if (wifiHelper.getWifiManager().isWifiEnabled()) {
+            wifiHelper.disableWifi(null);
+        }
 
         isHotspotInitiated = false;
         isHotspotRunning = false;

share_app/src/main/java/org/odk/share/controller/WifiHelper.java

@@ -92,7 +92,9 @@ private void removeNetworkAndEnableOther(String ssid) {
     }
 
     public void disableWifi(String ssid) {
-        removeNetworkAndEnableOther(ssid);
+        if (ssid != null) {
+            removeNetworkAndEnableOther(ssid);
+        }
         wifiManager.setWifiEnabled(false);
     }