title: How to add a notification settings activity to the system settings
body: <p>On Android 5.0 there is an option through <code>Settings -&gt; Sound &amp; notification -&gt; App notification -&gt; Calendar (for example)</code> to go directly to the notification settings of the app.<br>
  I also know it's a flag in the manifest as described in this <a href="https://www.youtube.com/watch?v=Uiq2kZ2JHVY" rel="noreferrer">DEV.BYTES talk</a>.<br>
  How can it be achieved, what is the flag used?</p>
  
  <p>Here is a screenshot for more clarification:<br>
  <img src="https://i.stack.imgur.com/j8SCa.png" alt="enter image description here"></p>