Added a hard variable called shouldRenderAvatars to gate the avatars rendering work for web. Gating this work will allow me to land all the diffs in this stack without launching avatars. I know this is a big diff; however, when we eventually have avatars in stable condition, I think it will be nice to get rid of this code, so having one diff that shows all the changes that need to be "reverted" is why I decided to make this diff bigger than normal.
Depends on D7276
