Update test-attachments.md
Update test-attachments.md

Update test doc after changes were made to how some audio and video files display and preview.
daizenberg/platform,cadecairos/mattermoz,rahulltkr/platform,rgarmsen2295/platform,daizenberg/platform,ttyniwa/platform,rompic/platform,kernicPanel/platform,trashcan/platform,rompic/platform,trashcan/platform,trashcan/platform,numericube/platform,mozilla/mattermoz,ZBoxApp/platform,npcode/platform,ZBoxApp/platform,mozilla/mattermoz,tbolon/platform,cadecairos/mattermoz,kernicPanel/platform,tbolon/platform,rgarmsen2295/platform,fosstp/platform,cyanlime/platform,tbalthazar/platform,42wim/platform,cyanlime/platform,samogot/platform,dotcominternet/platform,dimitertodorov/platform,dotcominternet/platform,ttyniwa/platform,rahulltkr/platform,mozilla/mattermoz,ZBoxApp/platform,fosstp/platform,mozilla/mattermoz,asaadmahmoodspin/platform,ttyniwa/platform,cyanlime/platform,tbalthazar/platform,asaadmahmoodspin/platform,ttyniwa/platform,ttyniwa/platform,kernicPanel/platform,cadecairos/mattermoz,rahulltkr/platform,rompic/platform,dotcominternet/platform,fosstp/platform,tbolon/platform,42wim/platform,cadecairos/mattermoz,daizenberg/platform,asaadmahmoodspin/platform,mozilla/mattermoz,numericube/platform,samogot/platform,dimitertodorov/platform,cyanlime/platform,rgarmsen2295/platform,kernicPanel/platform,rahulltkr/platform,samogot/platform,rgarmsen2295/platform,42wim/platform,ZBoxApp/platform,dimitertodorov/platform,npcode/platform,kernicPanel/platform,trashcan/platform,tbolon/platform,tbolon/platform,npcode/platform,cadecairos/mattermoz,fosstp/platform,npcode/platform,dotcominternet/platform,npcode/platform,tbalthazar/platform,rgarmsen2295/platform,ZBoxApp/platform,trashcan/platform,numericube/platform