Android: fix interface for "utf8" serializer

Author: Sefa Ilkimen

src/android/com/synconset/cordovahttp/CordovaHttp.java

@@ -145,7 +145,8 @@ protected HttpRequest setupDataSerializer(HttpRequest request) throws JSONExcept
           request.contentType(request.CONTENT_TYPE_JSON, request.CHARSET_UTF8);
           request.send(this.getParamsObject().toString());
       } else if (new String("utf8").equals(this.getSerializerName())) {
-          request.send(this.getParamsObject().toString());
+          request.contentType("text/plain", request.CHARSET_UTF8);
+          request.send(this.getParamsMap().get("text").toString());
       } else
       {
           request.form(this.getParamsMap());