title: Set the aggregation text of fragments from controller
body: <p>I have a xml-fragment. I set <code>items</code> as <code>"{path: '/idFamiglia' }"</code></p>
  
  <pre><code>&lt;core:FragmentDefinition
    xmlns="sap.m"
    xmlns:core="sap.ui.core"&gt;
    &lt;SelectDialog
      id="idSelectDialog"
      noDataText="Nessun dato"
      title="Suggerimento"
      search="handleLocalSearch"
      liveChange="handleLocalSearch"
      confirm="handleClose"
      close="handleClose"
      items="{
        path: '/idFamiglia'
      }"&gt;
      &lt;StandardListItem
        title="{title}"
        description="{description}"
        icon="" 
        iconDensityAware="false"
        iconInset="false"
        type="Active" /&gt;
    &lt;/SelectDialog&gt;
  &lt;/core:FragmentDefinition&gt;
  </code></pre>
  
  <p>From the controller I want set this string. I try in this methods:</p>
  
  <pre><code>handleValueLocalHelp : function(oEvent) {
          this.inputId = oEvent.oSource.sId;
          if (!this._oDialog) {
              this._oDialog = sap.ui.xmlfragment("ui5bp.view.fragment.HintLocalDialog",this);
          }
          //1
          sap.ui.getCore().byId("idSelectDialog").setAggregation("items", "{path: '/idFamiglia'}");
          //2
          this._oDialog.bindElement("/idFamiglia");
          //3
          sap.ui.getCore().byId("idSelectDialog").bindElement("/idFamiglia");
  
          this._oDialog.setModel(this.getView().getModel("hint"));
          // toggle compact style
          jQuery.sap.syncStyleClass("sapUiSizeCompact", this.getView(), this._oDialog);
          this._oDialog.open();
      },
  </code></pre>
  
  <p>I have some errors..</p>
  
  <ol>
  <li><code>Uncaught Error: Aggregation 'items' of Element sap.m.List#idSelectDialog-list used with wrong cardinality (declared as 0..n)</code> if I try the forst mode</li>
  <li>If I try the second mode it not change the string </li>
  <li>the same behavior</li>
  </ol>
  
  <p>How can I modify the aggregation string (<code>items</code> for example) from controller?</p>