Fix device advanced search

Device search button was not functioning due to a id mismatch. This
commit fixes the issue.

Fixes entgra/product-iots#7

components/device-mgt/org.wso2.carbon.device.mgt.ui/src/main/resources/jaggeryapps/devicemgt/app/pages/cdmf.page.device.search/search.hbs

@@ -82,7 +82,7 @@
                                         required.</label>
                                 </div>
                                 <div class="col-md-2 form-group wr-input-control col-fixed-right">
-                                    <button id="device-search-btn add-custom-param" class="wr-btn">Search</button>
+                                    <button id="device-search-btn" class="wr-btn">Search</button>
                                 </div>
                             </div>