Add profile setup to onboarding in web UI (#27829)

app/controllers/api/v1/accounts/credentials_controller.rb

@@ -16,6 +16,8 @@ class Api::V1::Accounts::CredentialsController < Api::BaseController
     current_user.update(user_params) if user_params
     ActivityPub::UpdateDistributionWorker.perform_async(@account.id)
     render json: @account, serializer: REST::CredentialAccountSerializer
+  rescue ActiveRecord::RecordInvalid => e
+    render json: ValidationErrorFormatter.new(e).as_json, status: 422
   end
 
   private