Add test to make sure channel stops when factory disposes
Add test to make sure channel stops when factory disposes

ppy/osu-framework,smoogipooo/osu-framework,ppy/osu-framework,peppy/osu-framework,peppy/osu-framework,smoogipooo/osu-framework,ppy/osu-framework,ZLima12/osu-framework,ZLima12/osu-framework,peppy/osu-framework