Ok, I just figured it out... It was just taking a few extra steps. I guess I was so use to my Evo I expected it to be a little more simpler. But I just had to tinker around a little bit more to figure it out. So here it is for anyone who was having the same issue I was.
- Go to your gmail account setting for your specific account > select (Labels to notify) at the very bottom.
- Then select (Inbox)
- Then select (Ringtone) and pick out your new notification sound.
Hope this helps out anyone else who was having issues like I was.