[lib/native] introduce XXL size to AvatarSize

Summary:
For the user profile avatar modal, we need a bigger avatar size (224x224)

Depends on D9365

Test Plan:
Confirmed the sizing with @ted, and this is what the avatar will look like:

emoji:

image:

Reviewers: atul, inka

Reviewed By: atul

Subscribers: ashoat, tomek, wyilio, ted

Differential Revision: https://phab.comm.dev/D9366