title: Kendo Grid - How to translate text "is true", "is false" in the column header?
body: <p>I have following column header in the grid (see image below):</p>
  
  <p><img src="https://i.stack.imgur.com/bMiGd.png" alt="enter image description here"></p>
  
  <p>I would like to ask, how can i translate "is true", "is false" strings?</p>
  
  <p>Many Thanks for any advice. </p>
  
  <p><strong>Columns:</strong></p>
  
  <pre><code> {
                      field :"active",
                      title : $translate.instant('ACTIVE'),
                      width:150,
                      filterable: {
                          cell: {
                              operator: "contains"
                          }
                      }
                  },
  </code></pre>
  
  <p><strong>Model:</strong></p>
  
  <pre><code> active: {
                                  editable: true,
                                  nullable: false,
                                  type: "boolean"
                              },
  </code></pre>