Set device as not ready onDestroy

src/android/LocalNotification.java

@@ -90,6 +90,15 @@ public class LocalNotification extends CordovaPlugin {
         isInBackground = false;
     }
 
+    /**
+     * The final call you receive before your activity is destroyed.
+     */
+    @Override
+    public void onDestroy() {
+        deviceready = false;
+        isInBackground = true;
+    }
+
     /**
      * Executes the request.
      *