Hide the default reactions of forum channels when we can't react with it

If you find a forum channel in which you don't have the permission to add reactions and that has a default reaction, and find a big enough post to be able to scroll down (or rotate your screen to paysage format), scroll down a bit and notice that the default reaction appears (in the bar showing up under the top bar), but if you click it, it will go away (because you still don't have the permission to add reactions). I've reported this as a bug to the support but they've asked me to post it as feedback (which is strange and surprising). It happens on Android, I'm not sure for the rest. And if you are on the Discord developers server, there are a few forum channels with default reactions we can't use.