The favicon can be provided in keycloak resources as favicon.ico, but AeroGear icon is in PNG format.

Keycloak doesn't provide a way how to configure the icon: https://github.com/keycloak/keycloak/blob/master/forms/common-themes/src/main/resources/theme/login/base/template.ftl#L13

We should either generate favicon.ico from favicon.png or ask keycloak to make this configurable.