title: Custom Notification Sound not working in Android Oreo
body: <pre><code>Uri sound = Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE + "://" + context.getPackageName() + "/" + R.raw.notification_mp3);
              mBuilder.setSound(sound);
  </code></pre>
  
  <p>I had copied the mp3 (notification_mp3.mp3) file into the raw folder in the res folder. When the notification is triggered it produces given mp3 sound upto <strong>Android Nougat</strong> but default sound in <strong>Android Oreo</strong>.
  I had referred many sites but nothing worked on <strong>Android Oreo</strong>. I didn't find any changes in Android Docs regarding notification sound in Android O &amp; above.
  What changes should be done to make this code working in Android O too?</p>