There is no spec-compliant way to remove remove/clear a user avatar

I think it would be useful to be able to set an avatar to null again with an event, but I don't see the option anywhere in the android client. Is it just not implemented yet on android or is it not in the spec yet?

Start by reading the Matrix avatar event specification and checking the Android client behavior described in the issue. Determine whether setting an avatar to null is already specified or requires a protocol change; done requires a clear specification decision and corresponding documented behavior.

Written by the indexing model from the issue text.