feat(service): clear source volume when change type (#4627)

* feat(service): clear source volume when change type

* feat(service): init volume source to the correct value

app/docker/views/services/create/createservice.html

@@ -309,8 +309,8 @@
                         <!-- volume-type -->
                         <div class="input-group col-sm-5" style="margin-left: 5px; vertical-align: top;">
                           <div class="btn-group btn-group-sm" ng-if="allowBindMounts">
-                            <label class="btn btn-primary" ng-model="volume.Type" uib-btn-radio="'volume'" ng-click="volume.name = ''">Volume</label>
-                            <label class="btn btn-primary" ng-model="volume.Type" uib-btn-radio="'bind'" ng-click="volume.Id = ''">Bind</label>
+                            <label class="btn btn-primary" ng-model="volume.Type" uib-btn-radio="'volume'" ng-click="volume.Source = null">Volume</label>
+                            <label class="btn btn-primary" ng-model="volume.Type" uib-btn-radio="'bind'" ng-click="volume.Source = null">Bind</label>
                           </div>
                           <button class="btn btn-sm btn-danger" type="button" ng-click="removeVolume($index)">
                             <i class="fa fa-trash" aria-hidden="true"></i>
@@ -333,7 +333,7 @@
                               ng-model="volume.Source"
                               ng-options="vol as ((vol.Id|truncate:30) + ' - ' + (vol.Driver|truncate:30)) for vol in availableVolumes"
                             >
-                              <option selected disabled hidden value="">Select a volume</option>
+                              <option selected disabled value="">Select a volume</option>
                             </select>
                           </div>
                           <div class="small text-warning" ng-show="!volume.Source"> <i class="fa fa-exclamation-triangle" aria-hidden="true"></i> Source is required. </div>