title: disableTooltip input on ngbTooltip is not disabling the tooltip
body: <p>I have an element with a tooltip which uses ngbTooltip</p>
  
  <pre><code>&lt;div ngbTooltip="Tooltip text" disableTooltip="tooltipDisabled" [placement]="['right-top']" container="body"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p><code>tooltipDisabled</code> is set to true in the typescript file. No matter how I try to modify this I can't get it to be disabled. <a href="https://ng-bootstrap.github.io/#/components/tooltip/api" rel="nofollow noreferrer">Here is the documentation</a> which mentions tooltipDisabled. I also can't find any examples/threads about <code>disableTooltip</code> anywhere.</p>
  
  <p><a href="https://github.com/ng-bootstrap/ng-bootstrap/blob/master/src/tooltip/tooltip.ts" rel="nofollow noreferrer">Here is ng-bootstrap/src/tooltip/tooltip.ts source code</a> if that helps. </p>